Question

Can somebody help me with this question

Answer 1

A solution is when the two lines intersect, when they have the same (x,y) point.  So we can say y=y which is the same as saying:

2x-15=5x

-3x-15=0

-3x=15

x=-5, now use either to solve for the y coordinate...y=5x becomes:

y=5(-5)=-25 so the solution is the point:

(-5, -25)

Answer 2

We start with:

y=2x-15
y=5x

Now, we have a perfectly set-up variable we can get rid of: y.

But we need to make either the top or bottom equation negative, so for simplicity, let's make the bottom one negative.

y=2x-15
(-y)=(-5x)

Now simplify.

-3x-15=0

Add 3x on both sides.

3x=15

Divide by 3 on both sides.

x=5