Question

The sum of the real numbers x and y is 11. their difference is 5. what is the value of xy? explain how you got your answer.

Answer 1

(1)x+y=11        given
(2)x-y=5           given
x=5+y              equality property of addition (add y to both sides of (2)
5+y+y=11         sub previous result in to (1)
2y=6                algebra and simplificatiuon
y=3                   division property of equality (divide both sides by 2)
x=8                    again sub previous into (1)