Question

Fie numerele naturale a si b care verifica relatiile : a + b =20 si a²-b²=200.
a) aflati cele doua umere

Answer 1

a+b=20
a²-b²=200
(a-b)(a+b)=200 
(a-b) × 20 = 200
a-b=10
a+b=20
2a=30
a=15
b=5