Question

1. $8sqrt{7} - (-5sqrt{7})$

Explanation:

Step1: Identify like radicals

Both terms have $\sqrt{7}$, so we can combine them. The expression is $8\sqrt{7}-(-5\sqrt{7})$. Subtracting a negative is adding the positive, so it becomes $8\sqrt{7} + 5\sqrt{7}$.

Step2: Combine like terms

Factor out $\sqrt{7}$: $(8 + 5)\sqrt{7}$. Then calculate $8 + 5 = 13$. So we get $13\sqrt{7}$.

Answer:

$13\sqrt{7}$