posted by jasmine20 on .
can someone help me plz...last problem
(7 + radical (5))(7- radical (5))
for this one i have no idea
(a+b)*(a-b)= a^2 - b^2
memorize that, it is the factors of the difference of squares.
In this case, a=7, b= sqrt5
so, it simplifies to 49-5=44
So , i don't always have to leave it in a radical form for the answers?