Solve for x
x=15
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140\times 3=x\times 28
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 140x, the least common multiple of x,140.
420=x\times 28
Multiply 140 and 3 to get 420.
x\times 28=420
Swap sides so that all variable terms are on the left hand side.
x=\frac{420}{28}
Divide both sides by 28.
x=15
Divide 420 by 28 to get 15.
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