1. **Problem 7: Solve for all values of $x$ to the nearest hundredth:**
Given equation:
$$\frac{x^2 - 3x + 2}{x + 3} = 5(x + 3)$$
2. **Step 1: Multiply both sides by $x + 3$ to eliminate the denominator:**
$$x^2 - 3x + 2 = 5(x + 3)^2$$
3. **Step 2: Expand the right side:**
$$(x + 3)^2 = x^2 + 6x + 9$$
So,
$$x^2 - 3x + 2 = 5(x^2 + 6x + 9)$$
4. **Step 3: Distribute 5:**
$$x^2 - 3x + 2 = 5x^2 + 30x + 45$$
5. **Step 4: Bring all terms to one side:**
$$x^2 - 3x + 2 - 5x^2 - 30x - 45 = 0$$
Simplify:
$$-4x^2 - 33x - 43 = 0$$
6. **Step 5: Multiply both sides by $-1$ to make the leading coefficient positive:**
$$4x^2 + 33x + 43 = 0$$
7. **Step 6: Use the quadratic formula:**
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=4$, $b=33$, $c=43$.
Calculate discriminant:
$$b^2 - 4ac = 33^2 - 4(4)(43) = 1089 - 688 = 401$$
8. **Step 7: Calculate roots:**
$$x = \frac{-33 \pm \sqrt{401}}{8}$$
$$\sqrt{401} \approx 20.024984$$
So,
$$x_1 = \frac{-33 + 20.024984}{8} = \frac{-12.975016}{8} = -1.62$$
$$x_2 = \frac{-33 - 20.024984}{8} = \frac{-53.024984}{8} = -6.63$$
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2. **Problem 8: Find the average rate of change over the interval $2 \leq t \leq 8$**
Given points:
At $t=2$, distance = 110 miles
At $t=8$, distance = 350 miles
Average rate of change formula:
$$\text{Average rate} = \frac{\text{Change in distance}}{\text{Change in time}} = \frac{f(8) - f(2)}{8 - 2}$$
Calculate:
$$= \frac{350 - 110}{6} = \frac{240}{6} = 40$$
So, the average rate of change is 40 miles per hour.
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3. **Problem 9: Solve for all values of $x$:**
Given:
$$3x^3 - 2x^2 - 27x + 18 = 0$$
4. **Step 1: Group terms:**
$$(3x^3 - 2x^2) - (27x - 18) = 0$$
5. **Step 2: Factor each group:**
$$x^2(3x - 2) - 9(3x - 2) = 0$$
6. **Step 3: Factor out common binomial:**
$$(x^2 - 9)(3x - 2) = 0$$
7. **Step 4: Factor difference of squares:**
$$(x + 3)(x - 3)(3x - 2) = 0$$
8. **Step 5: Solve each factor:**
$$x + 3 = 0 \Rightarrow x = -3$$
$$x - 3 = 0 \Rightarrow x = 3$$
$$3x - 2 = 0 \Rightarrow x = \frac{2}{3}$$
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4. **Problem 10: Solve for all values of $x$:**
Given:
$$x^4 + 6x^2 - 27 = 0$$
5. **Step 1: Substitute $y = x^2$ to reduce degree:**
$$y^2 + 6y - 27 = 0$$
6. **Step 2: Use quadratic formula for $y$:**
$$y = \frac{-6 \pm \sqrt{6^2 - 4(1)(-27)}}{2(1)} = \frac{-6 \pm \sqrt{36 + 108}}{2} = \frac{-6 \pm \sqrt{144}}{2}$$
$$= \frac{-6 \pm 12}{2}$$
7. **Step 3: Calculate $y$ values:**
$$y_1 = \frac{-6 + 12}{2} = 3$$
$$y_2 = \frac{-6 - 12}{2} = -9$$
8. **Step 4: Recall $y = x^2$, so solve:**
For $y_1 = 3$:
$$x^2 = 3 \Rightarrow x = \pm \sqrt{3} \approx \pm 1.73$$
For $y_2 = -9$:
$$x^2 = -9$$
No real solutions since square of real number cannot be negative.
**Final solutions:**
$$x = \pm 1.73$$
Quadratic And Polynomial E8422A
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