Question

a²-b²=7. Determine o valore de (a-b).

Answer 1

a²-b²=7

(a-b).(a+b) = 7

(a-b) = 7/(a+b) => chute lógico: a=4, b=3

(a-b) = 7/(4+3)

(a-b) = 1 ✓