Question

How do you simplify $\frac{3}{4x}+\frac{2}{5y}$ ?

Answer 1

You need to find the lowest common denominator and cross multiply.

Explanation:

Since the denominators (the lower part of the fractions) are different, you must find the lowest common denominator - that is the least common multiple.

In this case, there are no factors in common so you must just multiply the two denominators together to form your new denominator $(4x\times 5y$ which gives you $20xy).$

For the numerators (the top part of the fraction), you need to cross multiply. That means you must multiply each numerator by the denominator of the other fraction. Then, you add them together for your new numerator.

So for the first fraction, you multiply $3\times 5y.$ The second fraction, you multiply $2\times 4x.$

The resulting fraction is $\frac{8x+15y}{20xy}$