Decimal Coefficients

A decimal coefficient can be written as a fraction. The equation $0.5x = 3$ says that half of a number is 3. Since $0.5 = \frac{1}{2}$, dividing both sides by 0.5 is the same as multiplying both sides by 2.

$$x = 6$$

Multiplying by 2 undoes the coefficient 0.5. Check the answer: $0.5\cdot 6 = 3$.

You can write the coefficient as a decimal or as a fraction, whichever is easier. Dividing by 0.5 and multiplying by 2 give the same answer, because $0.5 = \frac{1}{2}$. Other useful pairs are $0.25 = \frac{1}{4}$ and $0.2 = \frac{1}{5}$.