Question

Graph A line goes through the point (6,–2) and has a slope of –3. What is the value of a if the point (a,7) lies on the line?

Answer 1

The value of a is 3

Explanation:

First you have to make an equation based on the point and slope that you were given. The formula for this is y-(y cordinate of point)=slope(x-x cordinate of slope)

y--2=-3(x-6), which simplifies to y+2=-3(x-6)

In (a,7), 7 is the y coordinate. We have to plug 7 in for the y in our equation.

7+2=-3(x-6),

Combine like terms on the left side to get to 9=-3(x-6)

Multiply out on the left to get 9=-3x+18

Subtract 18 from the left side to get -9=-3x

Divide both sides by negative 3 to get 3=x (remember x is a)