how do I solve -5x+y=-3; 3x-8y=24

Question

I need help learn this math

 

Answer 1

Hi Elizabeth,

 

The way to solve this kind of system of equations is to eliminate one of the variables by multiplying on or both of the equations with a number and then adding them up.

 

-5x + y = -3

3x - 8y = 24

 

I will multiply the first equation by 3 and the second one by 5 and then add them.

3*(-5x + y = -3)
5*(3x - 8y = 24)

-15x + 3y = -9

15x - 40y = 120

----------------------addition

    -37y = 111

y = -3

now plug in y in one of the original equations to find x.

-5x + y = -3

-5x + (-3) = -3

-5x = 0

x = 0