1. Find four consecutive even integers such that 4 times the sum of the first and fourth is 8 greater than 12 times the third.
Let the four consecutive even integers be $x$, $x+2$, $x+4$, and $x+6$.
The sum of the first and fourth is $x + (x+6) = 2x + 6$.
4 times this sum is $4(2x + 6) = 8x + 24$.
12 times the third integer is $12(x+4) = 12x + 48$.
According to the problem: $$8x + 24 = 12x + 48 + 8$$
Simplify the right side: $$8x + 24 = 12x + 56$$
Bring all terms to one side: $$8x + 24 - 12x - 56 = 0$$
Simplify: $$-4x - 32 = 0$$
Add 32 to both sides: $$-4x = 32$$
Divide both sides by $-4$: $$x = \frac{32}{\cancel{-4}}\cancel{-1} = -8$$
The integers are $-8$, $-6$, $-4$, and $-2$.
2. Galileo tried for a reasonable result but got $4 \frac{3}{5}$. If this was $2 \frac{3}{10}$ of his goal, what number was he trying for?
Convert mixed numbers to improper fractions:
$4 \frac{3}{5} = \frac{23}{5}$, $2 \frac{3}{10} = \frac{23}{10}$.
Let the goal be $G$.
Equation: $$\frac{23}{5} = \frac{23}{10} G$$
Divide both sides by $\frac{23}{10}$:
$$G = \frac{\frac{23}{5}}{\frac{23}{10}} = \frac{23}{5} \times \frac{10}{23}$$
Cancel $23$:
$$G = \cancel{\frac{23}{5}} \times \frac{10}{\cancel{23}} = \frac{10}{5} = 2$$
Galileo's goal was 2.
3. Paul wrestled at 125 pounds. Weight increased 16% in 1 year. Find new weight.
New weight = original weight + 16% of original weight
$$= 125 + 0.16 \times 125 = 125(1 + 0.16) = 125 \times 1.16 = 145$$
Paul wrestled at 145 pounds in ninth grade.
4. Carolyn plowed 67% of farm in 2 weeks, which is 268 acres. Find farm size.
Let farm size be $F$.
$$0.67 F = 268$$
Divide both sides by 0.67:
$$F = \frac{268}{0.67} \approx 400$$
Farm size is approximately 400 acres.
5. Seven-eighths of workers used scurrilous language. 400 did not. Find total workers.
Let total workers be $W$.
Workers not using scurrilous language = $\frac{1}{8} W = 400$
Multiply both sides by 8:
$$W = 400 \times 8 = 3200$$
Total workers = 3200.
6. 2 ∈ {What sets of numbers}?
2 is an integer, rational number, real number, complex number.
7. Solve $3 \frac{1}{8} x - 4 \frac{2}{5} = 7 \frac{1}{2}$.
Convert mixed numbers:
$3 \frac{1}{8} = \frac{25}{8}$, $4 \frac{2}{5} = \frac{22}{5}$, $7 \frac{1}{2} = \frac{15}{2}$.
Equation:
$$\frac{25}{8} x - \frac{22}{5} = \frac{15}{2}$$
Add $\frac{22}{5}$ to both sides:
$$\frac{25}{8} x = \frac{15}{2} + \frac{22}{5}$$
Find common denominator 10:
$$\frac{15}{2} = \frac{75}{10}, \quad \frac{22}{5} = \frac{44}{10}$$
Sum:
$$\frac{75}{10} + \frac{44}{10} = \frac{119}{10}$$
Divide both sides by $\frac{25}{8}$:
$$x = \frac{\frac{119}{10}}{\frac{25}{8}} = \frac{119}{10} \times \frac{8}{25} = \frac{119 \times 8}{10 \times 25} = \frac{952}{250}$$
Simplify numerator and denominator by 2:
$$\frac{952}{250} = \frac{476}{125} = 3 \frac{101}{125}$$
8. Solve $-[-2(x-4) - |-3|] = -2x - 8$.
Calculate $|-3| = 3$.
Inside bracket:
$$-2(x-4) - 3 = -2x + 8 - 3 = -2x + 5$$
So left side:
$$-[-2x + 5] = 2x - 5$$
Equation:
$$2x - 5 = -2x - 8$$
Add $2x$ to both sides:
$$4x - 5 = -8$$
Add 5 to both sides:
$$4x = -3$$
Divide both sides by 4:
$$x = \frac{-3}{4}$$
9. Write $0.000135 \times 10^{-17}$ in scientific notation.
$0.000135 = 1.35 \times 10^{-4}$
So:
$$1.35 \times 10^{-4} \times 10^{-17} = 1.35 \times 10^{-21}$$
10. Write $135,000 \times 10^{-17}$ in scientific notation.
$135,000 = 1.35 \times 10^{5}$
So:
$$1.35 \times 10^{5} \times 10^{-17} = 1.35 \times 10^{-12}$$
11. Add $\frac{a}{xy} + \frac{4}{x(x+y)}$.
Find common denominator $x y (x+y)$.
Rewrite:
$$\frac{a(x+y)}{x y (x+y)} + \frac{4 y}{x y (x+y)} = \frac{a(x+y) + 4 y}{x y (x+y)}$$
12. Simplify $\frac{a^0 (2x)^{-2}}{a^2 (4 a^0)^2}$.
Recall $a^0 = 1$.
Rewrite numerator:
$$(2x)^{-2} = \frac{1}{(2x)^2} = \frac{1}{4x^2}$$
Denominator:
$$(4 a^0)^2 = 4^2 = 16$$
Expression:
$$\frac{\frac{1}{4x^2}}{a^2 \times 16} = \frac{1}{4x^2} \times \frac{1}{16 a^2} = \frac{1}{64 a^2 x^2}$$
13. Simplify by adding like terms:
$$3x^2 y - \frac{4 x^{-2} y^{-2}}{x^{-4} y^{-3}} + \frac{5 x x}{y^{-1}} - \frac{3 x^2 y^2}{y^{-2}}$$
Simplify each term:
Second term:
$$\frac{4 x^{-2} y^{-2}}{x^{-4} y^{-3}} = 4 x^{-2 - (-4)} y^{-2 - (-3)} = 4 x^{2} y^{1} = 4 x^{2} y$$
Third term:
$$\frac{5 x x}{y^{-1}} = 5 x^{2} y^{1}$$
Fourth term:
$$\frac{3 x^{2} y^{2}}{y^{-2}} = 3 x^{2} y^{2 - (-2)} = 3 x^{2} y^{4}$$
Now sum:
$$3 x^{2} y - 4 x^{2} y + 5 x^{2} y - 3 x^{2} y^{4} = (3 - 4 + 5) x^{2} y - 3 x^{2} y^{4} = 4 x^{2} y - 3 x^{2} y^{4}$$
14. Solve system by substitution:
$$x + 3y = 16$$
$$2x - 3y = -4$$
From first: $$x = 16 - 3y$$
Substitute into second:
$$2(16 - 3y) - 3y = -4$$
$$32 - 6y - 3y = -4$$
$$32 - 9y = -4$$
$$-9y = -36$$
$$y = 4$$
Find $x$:
$$x = 16 - 3(4) = 16 - 12 = 4$$
Solution: $(x,y) = (4,4)$
15. Solve system by elimination:
$$N_N + N_D = 22$$
$$5 N_N + 10 N_D = 135$$
Multiply first by 5:
$$5 N_N + 5 N_D = 110$$
Subtract from second:
$$(5 N_N + 10 N_D) - (5 N_N + 5 N_D) = 135 - 110$$
$$5 N_D = 25$$
$$N_D = 5$$
Find $N_N$:
$$N_N + 5 = 22 \Rightarrow N_N = 17$$
16. Expand:
$$(x^{-2} y^{-2} / m^{2}) \left(x^{2} y^{2} m^{2} - \frac{3 x^{4} y^{-4}}{m^{-2}}\right)$$
Rewrite denominator in second term:
$$\frac{3 x^{4} y^{-4}}{m^{-2}} = 3 x^{4} y^{-4} m^{2}$$
Expression inside parentheses:
$$x^{2} y^{2} m^{2} - 3 x^{4} y^{-4} m^{2}$$
Multiply by $x^{-2} y^{-2} m^{-2}$:
$$x^{-2} y^{-2} m^{-2} \times x^{2} y^{2} m^{2} - x^{-2} y^{-2} m^{-2} \times 3 x^{4} y^{-4} m^{2}$$
Simplify each term:
First term:
$$x^{-2+2} y^{-2+2} m^{-2+2} = x^{0} y^{0} m^{0} = 1$$
Second term:
$$3 x^{-2+4} y^{-2-4} m^{-2+2} = 3 x^{2} y^{-6} m^{0} = 3 x^{2} y^{-6}$$
Result:
$$1 - 3 x^{2} y^{-6}$$
17. Simplify:
$$5 \sqrt{45} - 3 \sqrt{180} + 2 \sqrt{20}$$
Simplify radicals:
$$\sqrt{45} = \sqrt{9 \times 5} = 3 \sqrt{5}$$
$$\sqrt{180} = \sqrt{36 \times 5} = 6 \sqrt{5}$$
$$\sqrt{20} = \sqrt{4 \times 5} = 2 \sqrt{5}$$
Rewrite expression:
$$5 \times 3 \sqrt{5} - 3 \times 6 \sqrt{5} + 2 \times 2 \sqrt{5} = 15 \sqrt{5} - 18 \sqrt{5} + 4 \sqrt{5}$$
Combine:
$$(15 - 18 + 4) \sqrt{5} = 1 \sqrt{5} = \sqrt{5}$$
18. Solve:
$$\frac{x}{4} - \frac{x+2}{3} = 12$$
Multiply both sides by 12 (LCM of 4 and 3):
$$3x - 4(x+2) = 144$$
$$3x - 4x - 8 = 144$$
$$-x - 8 = 144$$
$$-x = 152$$
$$x = -152$$
19. Solve:
$$\frac{2y}{4} - \frac{y}{7} = \frac{y - 3}{2}$$
Simplify first term:
$$\frac{2y}{4} = \frac{y}{2}$$
Multiply entire equation by 28 (LCM of 2,7,2):
$$28 \times \left(\frac{y}{2} - \frac{y}{7}\right) = 28 \times \frac{y - 3}{2}$$
$$14 y - 4 y = 14 (y - 3)$$
$$10 y = 14 y - 42$$
$$10 y - 14 y = -42$$
$$-4 y = -42$$
$$y = \frac{42}{4} = 10.5$$
20. Solve:
$$\frac{p}{6} - \frac{2p}{5} = \frac{4p - 5}{15}$$
Multiply entire equation by 30 (LCM of 6,5,15):
$$30 \times \left(\frac{p}{6} - \frac{2p}{5}\right) = 30 \times \frac{4p - 5}{15}$$
$$5p - 12p = 2(4p - 5)$$
$$-7p = 8p - 10$$
$$-7p - 8p = -10$$
$$-15p = -10$$
$$p = \frac{10}{15} = \frac{2}{3}$$
21. Given:
$$R_A T_A + R_P T_P = 500$$
$$R_P = 25, T_P = 9, T_A = 5$$
Find $R_A$.
Substitute known values:
$$R_A \times 5 + 25 \times 9 = 500$$
$$5 R_A + 225 = 500$$
$$5 R_A = 275$$
$$R_A = \frac{275}{5} = 55$$
22. Evaluate:
$$\frac{\sqrt[3]{x}}{5}$$
Given:
$$\frac{x + 20}{5} = -21$$
Multiply both sides by 5:
$$x + 20 = -105$$
$$x = -125$$
Calculate cube root:
$$\sqrt[3]{-125} = -5$$
Evaluate expression:
$$\frac{-5}{5} = -1$$
25. Factor:
$$p^{2} - 55 - 6p$$
Rewrite:
$$p^{2} - 6p - 55$$
Find factors of -55 that sum to -6: -11 and 5.
Factor:
$$(p - 11)(p + 5)$$
26. Factor:
$$-30 - 13x + x^{2}$$
Rewrite in standard form:
$$x^{2} - 13x - 30$$
Find factors of -30 that sum to -13: -15 and 2.
Factor:
$$(x - 15)(x + 2)$$
27. Factor:
$$2 m^{2} - 24 m + 70$$
Factor out 2:
$$2 (m^{2} - 12 m + 35)$$
Find factors of 35 that sum to -12: -7 and -5.
Factor inside parentheses:
$$(m - 7)(m - 5)$$
Final factorization:
$$2 (m - 7)(m - 5)$$
28. Factor:
$$-x^{3} + 14 x^{2} - 40 x$$
Factor out $-x$:
$$-x (x^{2} - 14 x + 40)$$
Factor quadratic:
Find factors of 40 that sum to -14: -10 and -4.
$$-x (x - 10)(x - 4)$$
29. Factor:
$$4 m^{2} - 49 x^{2} p^{2}$$
Recognize difference of squares:
$$ (2 m)^{2} - (7 x p)^{2} = (2 m - 7 x p)(2 m + 7 x p)$$
Multiple Problems 5527Ad
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