Verified answer

Look at the answer.

√5 * √5 = 5

-8*2 = -16

5*-16 = -80

Answer: -80

What your multiplication above says is "What does -8 times square root 5 times 2 times sqrt(5) equal?"

It may appear that there is only one multiplication intended in the "L" step in foil, but there are actually four. Minus eight and root five are "coefficients" of each other, that is, they are intended multiplications, and two and the other root five are coefficients of each other.

Thus, using the commutative property of multiplication, you can multiply out the numbers in whatever order you would like. Done simply, you have:

-8 * sqrt(5) * 2 * sqrt(5) = -8 * 2 * 5 Remember sqrt(n) squared = n

= -16 * 5

= -80 Negative * Positive = Negative

So, it doesn't equal 80, but it does equal -80. Hope this helps :)

-8√5*2√5

= (-8* 2)(√5)^2

= (-16)*5

= -80

(Note: -8√5*6 = -48√5 but not -42√5 )

- (8√5)*(2√5)

= - 8*2*(√5)*(√5)

= - 16*5 = - 80