Răspuns :
8 x 4 + 9 x a = 86
= 32 + 9xa = 86
9xa = 86-32
9xa = 54
a= 54 : 9
a = 6
8 x 4 + 9 x 6 =
32 + 54
= 86
= 32 + 9xa = 86
9xa = 86-32
9xa = 54
a= 54 : 9
a = 6
8 x 4 + 9 x 6 =
32 + 54
= 86