Question

A line passes through the point (–2, 7) and has a slope of –5. What is the value of a if the point (a, 2) is also on the line?
A.–7
B.–1
C.1
D.7

Answer 1

Answer:

The correct option is B.

Step-by-step explanation:

The slope of a line is constant.

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

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

It is given that the line passes through (-2,7) and (a,2).

Using the above formula the slope of the line is

$m=\frac{2-7}{a-(-2)}$

$m=\frac{-5}{a+2}$

It is given that the slope of the line is -5. Substitute m=-5 in the above equation.

$-5=\frac{-5}{a+2}$

On cross multiplication we get

$-5(a+2)=-5$

Divide both sides by -5.

$a+2=1$

Subtract 2 from both the sides.

$a=1-2$

$a=-1$

The value of a is -1. Therefore the correct option is B.

Answer 2

Answer:

The answer is B.

Step-by-step explanation: