es. 11 mate, mi aiutereste? grazie in anticipo

Mi sembra di averti già risposto. Comunque..

(2·x + 5)^2 - (2·x + 3)^2=

=(4·x^2 + 20·x + 25) - (4·x^2 + 12·x + 9)=

=8·x + 16

------------------------------------------

(3·x + 2)^2 + (3·x + 1)·(3·x + 2 - 3)=

=(9·x^2 + 12·x + 4) + (9·x^2 - 1)=

=18·x^2 + 12·x + 3

-----------------------------------------------

(2·x + 3)·(3·x + 5) - (3·x + 5 - 4)·(2·x + 3 - 2)=

=(6·x^2 + 19·x + 15) - (3·x + 1)·(2·x + 1)=

=(6·x^2 + 19·x + 15) - (6·x^2 + 5·x + 1)=

=14·x + 14

=============================================================

11/a

$\small 2·2(2x+3)+2^2=$

$\small = 4(2x+3)+4=$

$\small = 8x+12+4=$

$\small = 8x+16$

11/b

$\small (3x+2)^2+(3x+1)(3x+2-3)=$

$\small 9x^2+12x+4+(3x+1)(3x-1)=$

$\small 9x^2+12x+4+9x^2\cancel{-3x}\cancel{+3x}-1=$

$\small 18x^2+12x+3$

11/c

$\small (2x+3)(3x+5) -(3x+5-2·2)(2x+3-2·1)=$

$\small =6x^2+10x+9x+15-(3x+5-4)(2x+3-2)=$

$\small =6x^2+19x+15-(3x+1)(2x+1)=$

$\small =6x^2+19x+15-(6x^2+3x+2x+1)=$

$\small =6x^2+19x+15-(6x^2+5x+1)=$

$\small =\cancel{6x^2}+19x+15\cancel{-6x^2}-5x-1=$

$\small =14x+14$