Question

Multiply and simplify the product:
(2sqrt7 - sqrt3)^2

Answer 1

it's simply (a-b)^2 = a^2 -2*a*b + b^2.

Answer 2

Is the anwer 31-2sqrt21??

Answer 3

i think it would be 4sqrt21 instead of 2

Answer 4

yeah it should be \[31-4\sqrt{21}\]

Answer 5

How so?

Answer 6

the middle term is 2*a*b, and a*b = 2rt7*rt3 = 2rt21
so 2*a*b = 2*2rt21