Math Problem Solver

$$\frac{126}{24} - \frac{21}{10} = \frac{63}{20} = 3.15$$

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of $\frac{126}{24}$ and $\frac{-21}{10}$ is $120$. $$\begin{aligned} \frac{126}{24} - \frac{21}{10} &= \frac{126 \cdot 5}{24 \cdot 5} + \frac{-21 \cdot 12}{10 \cdot 12} \\ &= \frac{630 + -252}{120} \\ &= \frac{378}{120} \\&= \frac{63}{20} \end{aligned}$$