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222-9+11+12:2*14+14 = ? ( )

## Toán Lớp 6: – (+84) +213 =-16 125: (3x – 13) = 25 .3(2x + 1) – 19 = 14 175 – 5(x + 3) = 85

Toán Lớp 6: – (+84) +213 =-16
125: (3x – 13) = 25
.3(2x + 1) – 19 = 14
175 – 5(x + 3) = 85

1. -(x+84)+213=-16
=>-(x+84)=-16-213
=>-x-84=-229
=>-x=-229+84
=>-x=-145
=>x=145
Vậy x=145
$\\$
125:(3x-13)=25
=>3x-13=125:25
=>3x-13=5
=>3x=5+13
=>3x=18
=>x=18:3
=>x=6
Vậy x=6
$\\$
3.(2x+1)-19=14
=>3.(2x+1)=14+19
=>3.(2x+1)=33
=>2x+1=33:3
=>2x+1=11
=>2x=11-1
=>2x=10
=>x=10:2
=>x=5
Vậy x=5
$\\$
175-5.(x+3)=85
=>5.(x+3)=175-85
=>5.(x+3)=90
=>x+3=90:5
=>x+3=18
=>x=18-3
=>x=15
Vậy x=15

2. Giải đáp:
125 : ( 3x – 13 ) = 25
3x – 13 = 125 : 25
3x – 13 = 5
3x = 5 + 13
3x = 18
x = 6
3( 2x + 1 ) – 19 = 14
3( 2x + 1 ) = 14 + 19
3( 2x + 1 ) = 33
2x + 1 = 33 : 3
2x + 1 = 11
2x = 11 – 1
2x = 10
x = 5
175 – 5( x + 3 ) = 85
5 ( x + 3 ) = 175 – 85
5 ( x + 3 ) = 90
x + 3 = 90 : 5
x + 3 = 18
x = 18 – 3
x = 15
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