Solution equation (4x / 5) * 1 / 4 + 2x / 5 = 12

4x/5*1/4+2x/5=12
x/5+2x/5=12
3x/5=12
x=12*5/3
x=20

In the inverse, 2 (x-1) = 4 (4x-1) of the distribution law of multiplication is used. If both sides of the equation are divided by 2 (x-1) at the same time, 1 = 2 is obtained. Why

2(x-1)=4(x-1)
Divide both sides by 2 (x-1) to get 1 = 2
The problem is: when both sides divide by a number or a formula, the number or formula can't be zero, because zero can't be divisor. Obviously, in this problem, X-1 = 0, that is, x = 1 is the solution of the original equation

How to solve the equation with 0.4x + 2 = 4.8

0.4x+2=4.8
X = (4.8-2) divided by 0.4
X = 2.8 divided by 0.4
X=7

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