Solve for x
x=5
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4=0.8x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x.
0.8x=4
Swap sides so that all variable terms are on the left hand side.
x=\frac{4}{0.8}
Divide both sides by 0.8.
x=\frac{40}{8}
Expand \frac{4}{0.8} by multiplying both numerator and the denominator by 10.
x=5
Divide 40 by 8 to get 5.
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