Solve for x
x=0.3
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7x=3.9-1.8
Subtract 1.8 from both sides.
7x=2.1
Subtract 1.8 from 3.9 to get 2.1.
x=\frac{2.1}{7}
Divide both sides by 7.
x=\frac{21}{70}
Expand \frac{2.1}{7} by multiplying both numerator and the denominator by 10.
x=\frac{3}{10}
Reduce the fraction \frac{21}{70} to lowest terms by extracting and canceling out 7.
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