Question

the sum of the number is 18 and their difference is 2. write a system of linear equations and solve the resulting system

Answer 1

Eqn 1: a + b = 18

Eqn 2: a - b = 2 -->Rearrange to isolate for a: a = 2+b

Sub into the first eqn: (2+b) + b = 18 --> 2 + 2b = 18 --> 2b = 16 --> b = 8

Thus with b = 8, a + b = 18 --> a + 8 = 18 --> a = 10