Question

(81:a+142:2):8=70:7 va rog

Answer 1

(81:a+142:2):8=70:7

(81:a+71):8=10

81:a+71=80

81:a=9

a=81:9=9

Answer 2

Răspuns:  a = 9

Explicație pas cu pas:

( 81 : a + 142 : 2 ) : 8 = 70 : 7

( 81 : a + 71 ) : 8 = 10

81 : a + 71 = 10 × 8

81 : a + 71 = 80

81 : a = 80 - 71

81 : a = 9

a = 81 : 9

a = 9 → numarul, aflat prin metoda mersului invers