SUPER URGENT!!!!!!!! I NEED HELP!!!!!1 PLSSSS!!!!!Use the linear combination method to solve the system of equations. Explain each step of your solution. 3x-8y=7" " &q…

Question

SUPER URGENT!!!!!!!! I NEED HELP!!!!!1 PLSSSS!!!!!Use the linear combination method to solve the system of equations. Explain each step of your solution. 3x-8y=7" " " " x+2y=-7

Answer 1

x=-3,y=-2

Explanation:

Given 2 expressions

S1:
`3x-8y=7`

S2:
`x+2y=-7`

Write one equation in terms of any variable (x or y)

Here I am writing S1 in terms of y

`3x-8y=7\\3x-7=8y\\y=(3x-7)/(8)`

Substitute this value of y as the value of y in S2

⇒
`x+2y=-7\\x+((3x-7)/(8) )*2=-7\\8x+6x-14=-56\\14x=-42\\x=-3`

Therefore
`x=-3`

Substitute this value of x in any of the expressions S1 or S2

Here i am substituting in S2

⇒
`x+2y=-7\\-3+2y=-7\\2y=(-7+3)\\2y=-4\\y=-2`

Therefore x=-3 and y=-2