Question

Tìm x biết: [ y x 81 + 2 x 81 - 3530 ] x 21 = 714

Answer 1

[(2+y)x81-3530]=714:21

[(2+y)x81-3530]=34

(2+y)x81=34+3530

(2+y)x81=3564

2+y=3564:81

2+y=44

y=44-2

y=42

Answer 2

[ y*81 +2*81-3530 ] *21 =714

y*81 +2*81-3530=714:21

81*(y+2)-3530=34

81*(y+2)=34+3530

81*(y+2)=3564

y+2=3564:81

y+2=44

y=44-2

y=42

Answer 3

[ y x 81 + 2 x 81 -3530 ] =714 :21

[ y x 81 + 2 x 81 -3530]= 34

y x 81 + 2 x 81 = 34 + 3530

y x 81 + 2 x 81 = 3564

y x 81 + 2 = 3564 : 81

y x 81 + 2 = 44

y x 81 = 44 -2

y x 81 = 42

y = 81 : 42

y = 2