Solve for x
x=25
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100+\left(x-5\right)\times 4=\left(5\times 20+4x\right)\times 0.9
Multiply 5 and 20 to get 100.
100+4x-20=\left(5\times 20+4x\right)\times 0.9
Use the distributive property to multiply x-5 by 4.
80+4x=\left(5\times 20+4x\right)\times 0.9
Subtract 20 from 100 to get 80.
80+4x=\left(100+4x\right)\times 0.9
Multiply 5 and 20 to get 100.
80+4x=90+3.6x
Use the distributive property to multiply 100+4x by 0.9.
80+4x-3.6x=90
Subtract 3.6x from both sides.
80+0.4x=90
Combine 4x and -3.6x to get 0.4x.
0.4x=90-80
Subtract 80 from both sides.
0.4x=10
Subtract 80 from 90 to get 10.
x=\frac{10}{0.4}
Divide both sides by 0.4.
x=\frac{100}{4}
Expand \frac{10}{0.4} by multiplying both numerator and the denominator by 10.
x=25
Divide 100 by 4 to get 25.
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