Question

If x + y = 2 and x - y = 6, solve for x and y.

Answer 1

Explanation:

Givens

x + y = 2

x - y = 6

Solution

Just add the two equations together. The y's will drop out.

x + y = 2

x - y = 6 Add

2x = 8 Divide by 2

2x/2 = 8/2 Combine

x = 4 Substitute x = 4 into the top equation

x + y = 2

4 + y = 2 Subtract 4 from both sides

4-4+y=2-4 Combine

y = - 2

Answer

x = 4

y = -2