a)(2x+3)²-(2x-3)(2x+3)+2(x-1)²=4x²+12x+9 - 4x²-9+2x²-4x+2=2x²+8x+2
b)(3√2+2√3)²+2(√3-√2)²-(√7+√5)(√7-√5)=(3√2)²+2x3√2x2√3+(2√3)²+2(3-2√6+2)-7-5=18+12√6+12+6-4√6+4-12=28 -8√6
la √5-√5copiezi ca la celalalt pana la +7 -5 astea le inlocuiesti cu minus 5plus 5=18+12√6+12+6-4√6+4=40 - 8√6
