Question

ПОМОГИТЕ ПОЖАЛУЙСТА!!! ​

Answer 1

Объяснение:

1.

(т+3)*т²-(т²-1)*т+4*(2-2т²)=т³+3т²-т³+т+8-8т²=-5т²+т+8=-(5т²-т-8).

2.

$\frac{x+4}{xy-x^2} +\frac{y+4}{xy-y^2} =\frac{x+4}{x*(y-x)} +\frac{y+4}{y*(x-y)} =\frac{x+4}{x*(y-x)} -\frac{y+4}{y*(y-x)} =\frac{y*(x+4)-x*(y+4)}{xy*(y-x)}=\\=\frac{xy+4y-xy-4x}{xy*(y-x)}=\frac{4y-4x}{xy*(y-x)}=\frac{4*(y-x)}{xy*(y-x)}=\frac{4}{xy} .$

3.

$9x+8x^2=-1\\8x^2+9x+1=0\\8x^2+8x+x+1=0\\8x*(x+1)+(x+1)=0\\(x+1)*(8x+1)=0\\x+1=0\\x_1=-1.\\8x+1=0\\8x=-1\ |:8\\x=-\frac{1}{8}.$

Ответ: x₁=-1     x₂=-1/8.

4.

$\frac{x-2}{2x-6}-\frac{x-1}{3x-9} = \frac{x-2}{2*(x-3)}-\frac{x-1}{3*(x-3)} =\frac{(x-2)*3-(x-1)*2}{2*3*(x-3)} =\frac{3x-6-2x+2}{6*(x-3)}=\frac{x-4}{6*(x-3)} .$