Question

Допоможіть будь ласка!!! (тільки 793,804,805,831)​

Answer 1

$\displaystyle\bf\\793)\\\\5x(a-y)-a+y=5x(a-y)-(a-y)=(a-y)(5x-1)\\\\\\804)\\\\3a+ab^{2}-a^{2} b-3b=(3a-3b)+(ab^{2}-a^{2} b)=3(a-b)+ab(b-a)=\\\\\\=3(a-b)-ab(a-b)=(a-b)(3-ab)\\\\\\805)\\\\4x^{2} y^{2} +5xz^{3} -20yz^{2} -x^{3} yz=(4x^{2} y^{2} -20yz^{2})+(5xz^{3} -x^{3} yz)=\\\\\\=4y(x^{2} y-5z^{2})+xz(5z^{2} -x^{2} y)= 4y(x^{2} y-5z^{2})-xz(x^{2} y-5z^{2} )= \\\\\\=(x^{2} y-5z^{2} )(4y-xz)\\\\\\831)$

$\displaystyle\bf\\(a-2)^{3} +8=(a-2)^{3} +2^{3}=(a-2+2)\cdot\Big[(a-2)^{2} -(a-2)\cdot 2+2^{2}\Big]=\\\\\\=a\cdot(a^{2} -4a+4-2a+4+4)=a\cdot(a^{2}-6a+12)$