Question

Afla nr. Necunoscute:
300-(2×a+57)=131

Answer 1

300-(2xa+57)=131⇔300-131=2xa+57⇔169=2xa+57⇔169-57=2xa ⇔112=2xa⇔112:2=a⇔56=a

Answer 2

2 x a + 57 =300 - 131
2 x a =169 - 57
2 x a =112
a =112 : 2
a =56