!!!!!!!!!!!!!!!!!!!!!!!!!!!
<span>(x+2)²-49=0
x2+4x+4-49=0
x2+4x-45=0
d=16+180=196
x=5
x=-9</span>
2cosa/sina * sin²a=2cosasina=sin2a
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)
(a+4)*2^2-(3a+4)(4-a)=(a+4)*4-(3a+4)(4-a)=4a+16-12a+3a^2+16-4a=-12a+32+3a^2=(-12)*2+32+3*2^2=24+32+12=68