Question

(1.)Find the slope of the line that passes through the given pair of points. (If an answer is undefined, enter UNDEFINED.) (?a + 3, b ? 3) and (a + 3, ?b) *******(2.)If the line passing through the points (a, 1) and (6, 5) is parallel to the line passing through the points (2, 7) and (a + 2, 1), what is the value of a?

Answer 1

Answer:

1. The slope of the line is $m=\frac{-2b+3}{2a}$.

2. The value of a is 18.

Step-by-step explanation:

If a line passes through two points, then the slope of the line is

$m=\frac{y_2-y_1}{x_2-x_1}$

(1)

It is given that the line passes through the points (-a + 3, b - 3) and (a + 3, -b). So, the slope of the line is

$m=\frac{-b-(b-3)}{a+3-(-a+3)}$

$m=\frac{-b-b+3}{a+3+a-3)}$

$m=\frac{-2b+3}{2a}$

The slope of the line is $m=\frac{-2b+3}{2a}$.

(2)

If the line passing through the points (a, 1) and (6, 5), then the slope of the line is

$m_1=\frac{5-1}{6-a}=\frac{4}{6-a}$

If the line passing through the points (2, 7) and (a + 2, 1), then the slope of the line is

$m_2=\frac{1-7}{a+2-2}=\frac{-6}{a}$

The slopes of two parallel lines are same.

$m_1=m_2$

$\frac{4}{6-a}=\frac{-6}{a}$

On cross multiplication we get

$4a=-6(6-a)$

$4a=-36+6a$

$4a-6a=-36$

$-2a=-36$

Divide both sides by -2.

$a=18$

Therefore the value of a is 18.