Question

Упростите выражение: (x+9)²-x(x-12)

Answer 1

${(x + 9)}^{2} - x^{2} (x - 12) = {x}^{2} + 18x + 81 - {x}^{2} + 12 = 30x + 81$

Answer 2

$x^2+18x+81+(-x^2+12x)$
$x^2+18x+81-x^2+12x$
$18x+81+0+12x$
$18x+81+12x$
$30x+81$