Question

Amy has $8 less than Maria.Together they have $30

Answer 1

 a + m = 30
a = m - 8

(m - 8) + m = 30
2m - 8 = 30
2m = 30 + 8
2m = 38
m = 38/2
m = 19

a = m - 8
a = 19 - 8
a = 11

so Amy has $11 and Maria has $ 19