Question

PLEASE HELP!!!

What is the solution of the system? Use substitution.
−4y − 3x = −11
x − 2y = 17

A. (−9 ,−4)
B. (9, 4)
C. (9, −4)
D. (−9, 4)

Answer 1

x=9, y=-4

C (9,-4)

Explanation:

−4y − 3x = −11

x − 2y = 17

WE are using substitution, so solve the second equation for x

Add 2y to each side

x -2y+2y = 17+2y

x = 17+2y

Substitute this into the first equation

-4y -3x = -11

-4y -3(17+2y) = -11

Distribute the 3

-4y -3*17 -3*2y = -11

-4y -51 -6y = -11

Combine like terms

-10y-51=-11

Add 51 to each side

-10y-51+51=-11+51

-10y = 40

Divide by -10

-10y/-10 = 40/-10

y = -4

Now we need to find x

x= 17+2y

x = 17+ 2(-4)

x =17-8

x=9