Question

Use the linear combination method to solve the system of equations. Explain each step of your solution.

-4x + 9y = 9
x - 3y = -6​

Answer 1

x=9 y=5

Explanation:

Let -4x+9y=9 be function 1 while x-3y=-6 be function 2

function 1 plus 4 times function 2

-4x+4x+9y-12y=-15

Simplify

-3y=-15

Divide each side by -3

y=5

Substitude y=5 into function 2

x-3(5)=-6

x-15=-6

add 15 to each side

x=9