Question

please answer my question​

Answer 1

7; 1 7 +

2 3 ans: 40

———

4 0

8; 2 7 + (-27)

27 - 2 = 0 { a+(-b) = a-b }

9;. -20 +0 = { -(a) +0 = (-a) }

-20

{any number +zero = that number }