Question

tìm x

a. 120 + ( 56 - 2x ) .3 = 156

b. 3x - 2^3 = 3^2 + 1^21

c. [( 6x - 72 ) : 2 - 84] 28 = 5628

Answer 1

[(6x - 72) : 2 - 84]. 28 = 5628

=> (6x - 72) : 2 - 84 = 5628 : 28 = 201

=> (6x - 72) : 2 = 201 + 84 = 285

=> 6x - 72 = 285 . 2 = 570

=> 6x = 570 + 72 = 642

=> x = 642 : 6

=> x = 107

Answer 2

sao nhiều bài zậy. Hỏi từng bài thôi

Answer 3

\(120+\left(56-2x\right).3=156\)

\(\left(56-2x\right).3=156-120\)

\(\left(56-2x\right).3=36\)

\(56-2x=36:3\)

\(56-2x=12\)

\(2x=56-12\)

\(2x=44\)

\(x=44:2\)

\(x=22\)

Answer 4

\(\text{Tìm }x\text{ : }\)

\(a,\text{ }120+\left(56-2x\right)\cdot3=156\)

     \(120+168-6x=156\)

     \(288-6x=156\)

     \(6x=288-156\)

     \(6x=132\)

     \(x=132\text{ : }6\)

     \(x=22\)

\(b,\text{ }3x-2^3=3^2+1^{21}\)

\(c,\text{ }\left\{\left(6x-72\right)\text{ : }2-84\right\}28=5628\)

     \(\left(3x-36-84\right)28=5628\)

     \(\left(3x-120\right)28=5628\)

        \(3x-120=5628\text{ : }28\)

        \(3x-120=201\)

        \(3x=201-120\)

        \(3x=81\)

        \(x=81\text{ : }3\)

        \(x=27\)