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x+2x+x=4
x + 2x + x=4
4x =4
x=4 : 4
x=1
Trl:
x + 2x + x = 4
( x + x ) + 2x = 4
2x + 2x = 4
4x = 4
x = 4 : 4
x = 1
Vậy x = 1
H c tốt