Question

Write the equation of a line with a slope of 2 that passes through the points (-2, -7) and (5, 7)

A. y-7=2x+5
B. y=2x
C. y=2x+3
D. y=2x-3

Answer 1

y=ax+b

(-2; -7); x=-2; y=-7

-7=-2a+b=> b=2a-7

(5; 7); x=5; y=7

7=5a+b

7=5a+2a-7 ; 7a=14=> a=2

b=2•2-7; b= -3

=> y=2x-3 D.

Answer 2

The answer to your question is letter D.

Explanation:

Slope = m = 2

Points A (-2, -7) B ( 5, 7)

1.- Check the slope

m =
`(y2 - y1)/(x2 - x1)`

`m = (7 + 7)/(5 + 2)`

`m = (14)/(7)`

m = 2

Then, the slope is correct

2.- Find the equation of the line

y - y1 = m (x - x1)

y + 7 = 2(x + 2)

y + 7 = 2x + 4

y = 2x + 4 - 7

y = 2x - 3