Question

Doprowadź do najprostszej postaci

. a) 2(1/2x-y)^2-6(2/3x+1)(2/3x-1)

b) -9(1/3x-y)^2-5(2/5x+y)(2/5x-y)

z góry dziękuje : )

Answer 1

2(1/2x-y)^2-6(2/3x+1)(2/3x-1)= 2(1/4x^2-y^2)- 6 [(2/3x)^2-1^2] = 1/2x^2-y^2- 6[4/9x^2-1]= 1/2x^2-y^2-2 2/3x^2-1= 3/6x^2-y^2-2 4/6x^2-1= -2 1/6x^2- y^2-1 

b) -9(1/3x-y)^2-5(2/5x+y)(2/5x-y)= -9(1/9*x^2-y^2)-5(2/5x)^2-y^2=1*x^2-y^2-5*4/25x^2-y^2=x^2-y^2-20/25x^2-5^2=x^2-y^2-(4/5x^2)-5^2= 1/5x^2 - 6y^2