Solve for x
x=30
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0.7x=21
Combine x and -0.3x to get 0.7x.
x=\frac{21}{0.7}
Divide both sides by 0.7.
x=\frac{210}{7}
Expand \frac{21}{0.7} by multiplying both numerator and the denominator by 10.
x=30
Divide 210 by 7 to get 30.
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