Question

1- CALCULE :
a) (7x+4y) * ( 7x-4y ) =
b) (9+5y)² = 
c) (12-2x)² = 
d) (14x+2y) * (14x-2y) =
e) (20x+10y)² =
f) (20x-10y)² =

Pf me ajudem , vale nota , obrigado ;) 

Answer 1

a) (7x+4y) * ( 7x-4y ) = 49x^2 - 16^2

b) (9+5y)² =  81 + 90y + 25y^2

c) (12-2x)² =   144 - 48x + 4x^2

d) (14x+2y) * (14x-2y) = 196 - 4y^2

e) (20x+10y)² = 400x^2 + 400xy+ 100y^2  

f) (20x-10y)² = 400x^2 - 400xy+ 100y^2