Algebra
posted by Leo on .
Can anyone please check the following for me please
Expand (5  2x) Squared
(5  2x) (5  2x)
5 sqrd + 5 X  2x + 2x x 5 + 2x X 2x
so
5 Sqrd  10x  10x + 4X
= 5 sqrd + 4x
Am I right..thank you :)

No, you should use FOIL
F  multiply the Firsts
O  multiply the Outers
I  multiply the Inners
L  multiply the Lasts
so (5  2x) (5  2x)
= (5)(5) + (5)(2x) + (2x)(5) + (2x)(2x)
= 25  20x + 4x^2