Answer
The value of a fraction does not change if both the numerator and the
denominator are divided (or multiplied) by the same nonzero number.
Work Step by Step
Fundamental Principle of Fractions:
The value of a fraction does not change if both the numerator and the
denominator are divided (or multiplied) by the same nonzero number.
So, $\displaystyle \frac{a\cdot c}{b\cdot c}=\frac{a}{c}.$
Examples of using the Principle:
reducing fractions: $\displaystyle \quad\frac{10}{15}=\frac{2\times 5}{3\times 5}=\frac{2}{5}$
expanding to a higher denominator:$\displaystyle \quad\frac{3}{7}==\frac{3\times 5}{7\times 5}=\frac{15}{35}$