Question

The sum of two numbers, x and y, is 12. The difference of x and two times y is 6. What are the values of x and y?

Answer 1

`x+y=12 \\ x-2y=6 \ \ \ \ \ \ \ \ \ |* (-1) \\ \\ x+y=12 \\ \underline{-x+2y=-6} \\ y+2y=12-6 \\ 3y=6 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ |/ 3 \\ y=2 \\ \\ x+y=12 \\ x+2=12 \ \ \ \ \ \ \ \ \ \ |-2 \\ x=10 \\ \\ \boxed{x=10, \ y=2}`