Question

Suma a doua nr este 120. Daca din primul nr scad 20 si ii adaug celui de-al doilea 20, nr sunt egale. Care sunt cele doua nr?

Answer 1

a+b=120
a-20=b+20 => a=b+20 +20=b+40

b+20+20+b=120
2×b+40=120-40
2×b=80
b=80:2
b=40

a=b+40
a=40+40
a=80

proba
80+40=120 (Adevarat )

80-20=40+20
60=60 ( Adevarat )

Answer 2

120-20-20=120-40=80
80:2=40   al doilea nr
120-40=80  primul nr