Đáp án:
Giải thích các bước giải:
a) $x^2+14x+49-y^2\\=(x^2+14x+49)-y^2\\=(x+7)^2-y^2\\=(x-y+7)(x+y-7)$
b) $9z^2-x^2+2xy-y^2\\=(9z^2)-(x^2-2xy+y^2)\\=(9z)^2-(x-y)^2\\=(9z-x+y)(9z+x-y)$
c) $6x^2+7x-3\\=6x^2+9x-2x-3\\=3x(2x+3)-(2x+3)\\=(3x-1)(2x+3)$
d) $x^2+11x+24\\=x^2+8x+3x+24\\=x(x+8)+3(x+8)\\=(x+3)(x+8)$