Question

Ajutor va rog dau coroana .
1.Calculați :
-11x+17x-20x
2.Decompuneti in factori expresia : 9x^2 - 4y^2

Answer 1

1)
 -14x
2) 
$(3x)^{2} - (2y)^{2} = (3x)^{2} +6xy-6xy- (2y)^{2}$
=$3x(3x+2y)-2y(3x+2y)=$
=(3x_2y)(3x-2y)

Answer 2

1)-11x+17x-20x=6x-20x=-14x
2)9x^2-4y^2=(3x-2y)(3x+2y)