Question

упростить:
(2х-7)(2х+7)+(3х-7)^2 +50х

Answer 1

$\displaystyle\bf\\(2x-7)(2x+7)+(3x-7)^{2}+50x=(2x)^{2} -7^{2}+\Big[(3x)^{2} -2\cdot 3x\cdot 7+7^{2} \Big]+50x=\\\\=4x^{2}-49+9x^{2} -42x+49+50x=13x^{2} +8x$