Question

-7 X minus 2Y equals -13 X minus 2Y equals 11

Answer 1

Answer:

Looking at the equation, x+y=8, I can subtract either x or y from both sides to get the following two equations:

x = 8 - y, or y = 8 - x.

So I now have an expression which I can substitute for either x or y.

Now, looking at the equation, 2x + y = 11, I can substitute either way:

2x + y = 11 2x + y = 11

2 (8 - y) + y = 11 2x + (8 - x) = 11

16 - 2y + y = 11 2x + 8 - x = 11

-2y + y = 11 - 16 2x - x = 11 - 8

-y = -5 therefore y = 5 x = 3

Now, to check our work: x + y = 3 + 5 = 8

and: 2x + y = (2 * 3) + 5 = 6 + 5 = 11