Solve for x
x=24
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0.9x-21-0.2x=-4.2
Subtract 0.2x from both sides.
0.7x-21=-4.2
Combine 0.9x and -0.2x to get 0.7x.
0.7x=-4.2+21
Add 21 to both sides.
0.7x=16.8
Add -4.2 and 21 to get 16.8.
x=\frac{16.8}{0.7}
Divide both sides by 0.7.
x=\frac{168}{7}
Expand \frac{16.8}{0.7} by multiplying both numerator and the denominator by 10.
x=24
Divide 168 by 7 to get 24.
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