Question

A line passes through the point (-2,7) and had a slope of -5

What is the value of a if the point (a,2) is also on the line
-7
-1
1
7

Answer 1

a = -1

Explanation:

The general equation for a straight line is y = mx+c, where m is the gradient/ slope, so m = -5. The first thing we need to do is find c, which we do by plugging in the x and y values that we already know: y = 7 and x = -2

7 = -5*(-2) + c

7 = 10 + c

c = 7-10 = -3

Now, we have the general equation of y = -5x -3 and we can use this to find a.

We'll treat a as x and y will be equal to 2:

2 = -5a -3

5 = -5a (Divide both sides by 5)

-a = 1 (now by -1)

a = -1

Answer 2

b. -1

Explanation:

you find the point and then go down 5 vertically within one horizontally to show the -5 slope and it will leave you at (-1, 2)