Question

calculați (x+3)²-(x-2)²​

Answer 1

${x}^{2} + 6x + 9 - {x}^{2} + 4x - 4 = 10x + 5 = 5(2x + 1)$

Answer 2

$\bf (x+3)^{2}-(x-2)^{2}=$

$\bf [(x+3)-(x-2)]\cdot [(x+3)+(x-2)] =$

$\bf [x+3-x+2]\cdot [x+3+x-2] =$

$\bf (3+2)\cdot (2x+1) =$

$\boxed{ \bf 5(2x+1)}$

Am folosit formula: a² - b² = (a+b)(a-b)