6х+9-12х+4=31
-6х-13=31
-6х=18
х= -3
1) ax^2+ay^2-bx^2-by^2+b-a =a*(x²+y²)-b(x²+y²) +b-a =
= (x²+y²)(a-b) -(a-b)=(a-b)*(x²+y²-1)
2) <span>xy^2- by^2- ax+ ab+ y^2- a =у</span>²(х-b+1)-а(x-b+1)=(х-b+1)*(у²-а)
1. 64-16x+x^2
2. 2x^2+6x-x-3=2x^2+5x-3
3. б
4. (х-1)^2-(х-2)(х+2)=
х^2-2х+1-х^2+4=
-2х+5
5. у (0)=2*0+4=4
у (3)=2*3+4=6+4=10
6. (0.49-х^2)=(0.7-х)(0.7+х)
2а < 2
a < 1
2) -3b<2
b>-2/3