Question

Solve each system by substitution. y = 2x + 5 3x - y= -6

Answer 1

X=-1 and y=3

To solve this, because y is equal to 2x+5, you can substitute 2x+5 into the bottom equation for y.

You now have 3x - (2x + 5) =-6

This can be solved like a normal equation. Multiply each term in the parenthesis by -1.

3x - 2x - 5 = -6

Subtract 2x from 3x

x - 5 = -6

Add 5 to both sides

x=-1

Now you can solve for y by plugging -1 in for x in either equation. Im going to use the top one.

y= 2(-1)+5
y= -2+5
y=3

You can check your answer by plugging in the values for x and y into both equations and making sure both sides equal each other.