Line Properties
1. Problem 24: Find the x- and y-intercepts of the given line.
Given the graph description, the line passes through x-intercept roughly at $x=3$ and y-intercept roughly at $y=-2$.
Therefore, the intercepts are $x=3$ and $y=-2$.
Answer: A) 3 and -2
2. Problem 25: Find the slope of a line passing through points $(a,b)$ and $(a,c)$.
The slope formula is $m=\frac{y_2-y_1}{x_2-x_1}$.
Here, $x_1=a$ and $x_2=a$, so denominator is zero.
Slope is undefined when denominator is zero.
Answer: B) undefined
3. Problem 26: Find the slope of the line $y = -4(x+2)$.
Rewrite as $y = -4x - 8$.
The slope is the coefficient of $x$ which is $-4$.
Answer: C) -4
4. Problem 27: Find the equation of a line passing through $(0,-2)$ with slope $-2$.
Using point-slope form: $y - y_1 = m(x - x_1)$.
Substitute: $y + 2 = -2(x - 0)$.
Simplify: $y + 2 = -2x$.
Rewrite: $2x + y + 2 = 0$.
Answer: C) 2x + y + 2 = 0
5. Problem 28: Find the equation of the line perpendicular to $x + 2y = 0$ and passing through $(0,-1)$.
First, find slope of $x + 2y = 0$.
Rewrite: $2y = -x$ or $y = -\frac{1}{2}x$, so slope is $-\frac{1}{2}$.
The perpendicular slope is the negative reciprocal: $2$.
Using point-slope form with point $(0,-1)$:
$y - (-1) = 2(x - 0)$ or $y + 1 = 2x$.
Rearranged: $2x - y + 1 = 0$, equivalent to $2x - y - 1=0$ changing signs.
Comparing options, correct is $2x - y -1=0$, which matches A) if we carefully check signs.
Option A) is $2x - y - 1=0$ which matches our derivation.
Answer: A) 2x - y - 1 = 0
6. Problem 29: Which point lies in the third quadrant?
Third quadrant means both $x<0$ and $y<0$.
Check options:
A) (2,5) both positive, 1st quadrant.
B) (2,-5) $x>0$, $y<0$, 4th quadrant.
C) (-2,5) $x<0$, $y>0$, 2nd quadrant.
D) (-2,-5) both negative, 3rd quadrant.
Answer: D) (-2,-5)
7. Problem 30: If two lines are perpendicular, then the product of slopes is $-1$.
This is a fundamental property of perpendicular lines.
Answer: B) product of their slopes is -1