Tìm x :
a, ( X x X ) x 4 = 406 - 12 : 2
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b, ( X - 248 ) : 3 = 3102
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a) ( X x X ) x 4 = 406 - 12 : 2
( X x X ) x 4 = 406 - 6
( X x X ) x 4 = 400
X x X = 400 : 4
X x X = 100
Vì X = X nên X = 100 : 2
X = 50
b) ( X - 248 ) : 3 = 3102
X - 248 = 3102 : 3
X - 248 = 1034
X = 1034 + 248
X = 1282