1a
-(x+1)+(2x+4)=-x-1+2x+4=x+3
b]
3(a²-4)-(a²+2)=3a²-12-a²-2=2a²-14=
c]
2(a+3b)-4a(2-7b)=2a+6b-8a+28ab=-6a+6b+28ab
d]
(2a+4)(3b+7a-3)=6ab+14a²-6a+12b+48a-12=14a²+42a+12b+6ab-12
zad.2:
3x²-6x+7
x=2
3×2²-6×2+7=27-12+7=22
1.
a)-(x+1)+(2x+4)=-x-1+2x+4=x+3
b)2(a2-4)-(-a2+2)=2a2-8+a2-2=3a2-10
c)2(a+3b)-4a(2-7b)=2a+6b-8a+28b=-6a+34b
d)(2a+4)*(3b+7a-3)=2ab+14a2-6a+12b+28a-12=14ab+14a2+22a-12
3x2-6x+7=3*2*2-6*2+7=12-12+7=7
