4. a) 2-3x supra x^2 - x + 2 supra x-1 + 5 supra 3x=
3(2-3x) + 6x +5(x-1) supra 3× • (x-1)=
6-9x+6x+5(x-1) supra 3× • (x-1)=
6-9x+6x+5x-5 supra 3x • (x-1)=
6-9x+6x+5x-5 supra 3x^2 -3x=
1-9x+6x+5x supra 3x^2-3x=
1+2x supra 3x^2-3x
b)(x+2) •(x-1)-(x-2) •(x+3) supra(x-2) •(x+2)=
x^2-x+2x-2(x^2+3x-2x-6)-2 supra x^2-4 =
x^2 -x+2x-2(x^2+x-6) -2 supra x^2-4=
x^2-x+2x-2-x^2-x+6-2 supra x^2 -4=
0+2 supra x^2-4=
2 supra ×^2-4
5. a)x+1 supra x+3- x-5 supra 2(x+3)- 4x supra 2(x^2-9) - x-2 supra 2(x-3)=
x+1 supra x+3 - x-5 supra 2(x+3) - 2x supra x^2-9 - x-2 supra 2(x-3)=
x+1 supra x+3 - x-5 supra 2(x+3) - 2× supra (x-3) •(x+3) - x-2 supra 2(x-3)=
(2x-6) •(x-1)-x(-3) •(x-5)-4x-(x+3) •(x-2) supra 2(x+3) •(x-3)=
(2x-6) •(x+1)-(x^2-5x-3x+15)-4x-(x^2-2x+3x-6) supra 2(x^2-9)=
2x^2+2x-6x-6(x^2-8x+15)-4x-(x^2+x-6) supra 2(x^2-9)=
2x^2+2x-6x-6-(x^2-8x+15)-4x-x^2-x+6 supra 2(x^2-9)=
2x^2+2x-6x-x^2+8x-15-4x-x^2-x supra 2(x^2-9)=
0-x-15 supra 2(x^2-9)=
-x-15 supra 2(x^2-9)=
-x+15 supra 2(x^2-9)=
-x+15 supra 2x^2-18
b) 7x supra 2(x+1) - 3x+5 supra 3(x+1) - 2-3x supra x+1 - x+6 supra 6(x+1)=
21-2(3x+5)-6(2-3x)-(x+6) supra 6(x+1)=
21x-6x-10-12+18x-x-6 supra 6(x+1)=
32-28 supra 6(x+1)=
2(16x-14) supra 6(x+1)=
16x-14 supra 3(x+1)=
16x-14 supra 3x+3
