Question

Find two numbers a and b whose sum a + b is -2 and whose difference a - b is 2

Answer 1

a=0 b=-2

Explanation:

a + b = -2 ……（1）

a - b = 2 …… （2）

（1）- （2）：

2b ＝-4

b = -2

a=-2-（-2）=0