The linear combination method is the same as the elimination method. Let's multiply the second equation by -2 so the x terms cancel each other out. When we do that we get a system of

and

. The x-terms cancel each other out giving us

and y = -3. Now sub -3 into one of the equations to solve for x. x+2(-3)=-4, and x - 6 = -4. x = 2. So the solution for our system is (2, -3)
Replace x in each equation and see which ones are true.
The answers are:
C. If 5x + 10 =20 then x =2
D. If 6x-12=48, then x=10
F. If 8x(x-4)=32, then x=8
Answer:
Not equivalent
Step-by-step explanation:
Distribute the negative in the parentheses. It basically multiplying everything inside by -1.

add like terms

Not equivalent since the 6x is positive
the surface area of that rectangular prism is 247.5.
Answer:16.5
Step-by-step explanation: