Question

8.4 add, subtract, and multiply radical expressions
score: 18.8/22 answered: 19/22
question 20
expand and simplify.
(-8 + \sqrt{6})(-8 - \sqrt{6}) =

Explanation:

Step1: Apply difference - of - squares formula

We know that $(a + b)(a - b)=a^{2}-b^{2}$. Here $a=-8$ and $b = \sqrt{6}$. So, $(-8+\sqrt{6})(-8 - \sqrt{6})=(-8)^{2}-(\sqrt{6})^{2}$.

Step2: Calculate the squares

$(-8)^{2}=64$ and $(\sqrt{6})^{2}=6$. Then $(-8)^{2}-(\sqrt{6})^{2}=64 - 6$.

Step3: Subtract

$64-6 = 58$.

Answer:

$58$