Question

Find the value of x in the following system of equations:

2x - 3y = 9
x = 4 + y

a.) x = -1
b.) x = 1
c.) x = 3
d.) x = 2

Answer 1

c.) x = 3

Explanation:

2x - 3y = 9

x = 4 + y

Substitute the second equation into the first equation

2(4+y) - 3y = 9

Distribute

8+2y -3y =9

8-y = 9

Subtract 8 from each side

8-y-8 =9-8

-y = 1

Multiply by -1

y =-1

Now solve for x

x = 4-1

x =3