Ответ:
-80
Объяснение:
p(6x)=6x+2
p(x+5)=x+2+5=x+7
2*(6x+2-6*(x+7))=2*(6x+2-6x-42)=-80
1)
(2x - 9)(x + 6) - x(x + 6) = 0
(x+6)(2x-9-x)=0
(x+6)(x-9)=0
x+6=0 x-9=0
x= - 6 x=9
2)
(8x+ 4)(x - 10) + (10 - x)(x - 8) = 0
(8x+ 4)(x - 10) - (x - 10)(x - 8) = 0
(x-10)(8x+4-x+8)=0
(x-10)(7x+12)=0
x-10=0 7x+12=0
x=10 7x= - 12 /:7
x= - 12/7
1) (x-2)²-(x-1)(x+2)=x²-4x+4-x²-2x+x+2=-6x+6=6(1-x)
2)5x+5y=12
x-2y=-7, x=-7+2y
5(-7+2y)+5y=12
-35+10y+5y=12
15y=47
y=47/15
x=-7+2*47/15=-105+94/15=-11/15
(-11/15;47/15)