Question

am nevoie de ajutor sunt in cl 7 si am facut lectie noua dar nu am inteles cum se fac exercitiile,va rog cine poate sa imi explice si mie. Calculati,utilizand formulele de calcul prescurtat: a)(1+x)²+(2+x)²+(3+x)²; b)(2x+3y)²+(2x+3y)(2x-3y);c)(2x+3y)²+4x(3x-2)+(2x-1)². va multumesc

Answer 1

[tex]a)(x+1)^2+(x+2)^2+(x+3)^2= \\ x^2+1+2x+x^2+4+4x+x^2+9+6x=\boxed{3x^2+12x+14} \\ \\ b)(2x+3y)^2+(2x+3y)(2x-3y)= \\ 4x^2+9y^2+12xy+4x^2-9y^2=8x^2+12xy=\boxed{4x(2x+3y)} \\ \\ c)(2x+3y)^2+4x(3x-2)+(2x-1)^2= \\ 4x^2+9y^2+12xy+12x^2-8x+4x^2+1-4x= \\ \boxed{20x^2+9y^2+12xy-12x}[/tex]