7 x 5 x X x ( 5 x 6 ) = 2100
35 x X x 30 = 2100
35 x X = 2100 : 30
35 x X = 70
X = 70 : 35
X = 2
7.5.x.30=2100
35.x=2100:30
35.x=70
x=70:35
x=2
Vậy x=2
7 x 5 x X x ( 5 x 6 ) = 2100
35 x X x 30 = 2100
35 x X = 2100 : 30
35 x X = 70
X = 70 : 35
X = 2
7 * 5 * x * ( 5 * 6 ) = 2100
35 * x * 30 = 2100
1050 * x = 2100
x = 2100 : 1050
x = 2
x:7*5*x*30=2100
x:7*5*x=2100:30=70
x:7*5*x=70