1. Problem: Find the x-coordinate of the line with slope $-2$ passing through $(3,7)$ when $y=17$.
Step 1: Use point-slope form: $y - y_1 = m(x - x_1)$.
Step 2: Substitute $m=-2$, $x_1=3$, $y_1=7$: $y - 7 = -2(x - 3)$.
Step 3: Simplify: $y - 7 = -2x + 6$ so $y = -2x + 13$.
Step 4: Set $y=17$: $17 = -2x + 13$.
Step 5: Solve for $x$: $-2x = 4$ so $x = -2$.
Answer: (b) $-2$.
2. Problem: Determine the relationship between lines $2x - 3y + 1 = 0$ and $4x - 6y + 1 = 0$.
Step 1: Find slopes: slope $m_1 = \frac{2}{3}$, slope $m_2 = \frac{4}{6} = \frac{2}{3}$.
Step 2: Slopes are equal, check constants: lines differ in constant term, so they are parallel but not coincident.
Answer: (a) parallel.
3. Problem: Find $c$ so lines $2x + cy - 3 = 0$ and $4x - 9y + 1 = 0$ are perpendicular.
Step 1: Slopes: $m_1 = -\frac{2}{c}$, $m_2 = \frac{4}{9}$.
Step 2: For perpendicular lines, $m_1 \times m_2 = -1$.
Step 3: $-\frac{2}{c} \times \frac{4}{9} = -1$.
Step 4: Simplify: $-\frac{8}{9c} = -1$ so $\frac{8}{9c} = 1$.
Step 5: Solve for $c$: $9c = 8$ so $c = \frac{8}{9}$.
Answer: (c) $\frac{8}{9}$.
4. Problem: Find equation of line crossing x-axis at $-3$ and parallel to $7y=11$.
Step 1: $7y=11$ is horizontal line $y=\frac{11}{7}$.
Step 2: Parallel line is also horizontal, so $y = k$.
Step 3: Crossing x-axis at $-3$ means point $(-3,0)$ lies on line.
Step 4: Horizontal line through $(-3,0)$ is $y=0$.
Answer: (d) none of the given options.
5. Problem: Equation of line through $(3,4)$ parallel to x-axis.
Step 1: Lines parallel to x-axis are horizontal: $y = k$.
Step 2: Passes through $(3,4)$ so $y=4$.
Answer: (c) $y=4$.
6. Problem: Solve system $x - 2y + \frac{1}{2} = 0$ and $2x - 4y + 1 = 0$.
Step 1: Multiply first equation by 2: $2x - 4y + 1 = 0$.
Step 2: Second equation is same: system is dependent.
Step 3: Infinite solutions.
Answer: (c) infinite solutions.
7. Problem: Find $c$ so lines $2y - x + 5=0$ and $(1+c)x + y + 2=0$ are parallel.
Step 1: Rewrite first line: $2y = x - 5$ so $y = \frac{x}{2} - \frac{5}{2}$, slope $m_1=\frac{1}{2}$.
Step 2: Rewrite second line: $y = -(1+c)x - 2$, slope $m_2 = -(1+c)$.
Step 3: For parallel lines, $m_1 = m_2$.
Step 4: $\frac{1}{2} = -(1+c)$ so $1+c = -\frac{1}{2}$.
Step 5: $c = -\frac{3}{2}$.
Answer: (b) $-\frac{3}{2}$.
8. Problem: Determine relation of lines $3x - y + 2=0$ and $2x - y - 3=0$.
Step 1: Slopes: $m_1 = 3$, $m_2 = 2$.
Step 2: Slopes not equal, product $3 \times 2 = 6 \neq -1$.
Step 3: Lines are neither parallel nor perpendicular nor identical.
Answer: (d) neither.
9. Problem: Graph of $y = -2$ is line?
Step 1: $y = -2$ is horizontal line.
Step 2: Horizontal lines are parallel to x-axis.
Answer: (a) parallel to the x-axis.
10. Problem: Equation of line parallel to y-axis passing through $(4,3)$.
Step 1: Lines parallel to y-axis are vertical: $x = k$.
Step 2: Passes through $(4,3)$ so $x=4$.
Answer: (b) $x=4$.
11. Problem: Points $(-1,4)$, $(1,5)$, $(3,y)$ collinear, find $y$.
Step 1: Find slope between first two points: $m = \frac{5-4}{1+1} = \frac{1}{2}$.
Step 2: Use slope to find $y$: $m = \frac{y-5}{3-1} = \frac{y-5}{2}$.
Step 3: Set equal: $\frac{1}{2} = \frac{y-5}{2}$.
Step 4: Multiply both sides by 2: $1 = y - 5$.
Step 5: $y = 6$.
Answer: (c) 6.
Lines Relations
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