Question

Coroana !!!! Repede !!! Calculati utilizand formule de calcul prescurtat :,a) (2x+3y)^2+4x(3x-2)+(2x-1)^2 ; b) (3a+2b)^2+(2a+b)(2a-b)-(3a-b)^2 ; c) (2-3x)^2+(2+3x)^2-(2x-3)^2-(4x+3)(4x-3) ; d) (2x^2+y)^2-(2x^2-y)^2+(x+y)(x-y). PS: "^2"= la puterea 2....

Answer 1

a)(2x+3y)²+4x(3x-2)+(2x-1)²=
[(4x)²+12xy+9y²]+(12x²-8x)+(4x²-4+1)=
16x²+12xy+9y²-4x-8

b)(3a+2b)²+(2a+b)(2a-b)-(3a-b)²=
(9a²+12ab+4b²)+(4a²+2ab-2ab+b²)-(9a²+6ab+b²)=
9a²+12ab+4b²-4a²+b²-9a²++6ab-b²
-4a²+4b²
18ab

c)(2-3x)²+(2+3x)²-(2x-3)²-(4x+3)(4x-3)=
(4-12x+9x²)+(4+12x+9x²-(4-12x+9x²)-(16x²-12x+12x-9+)=
(4-12x+9x²+4+12x+9x²-4+12x-9x²-46x²-9)=
9x²-16x²+9-8x

-7x²-8x+13
sucees