1. (9у2-5у+4)-(4у2-7)= 9у2-5у+4-4у2+7=5у2-5у+11
2. 5х2(3х-х7)=15х3-5х9
3. 8х-(2х+4)=2(3х-2)
8х-2х-4= 6х-4
8х-2х-6х=4-4
х=0
4. 5с+10вс=5с(1+2в)
14х2у+28ху3=14ху(х+2у2)
<span> 5^(2x+1)-5^2x=10x+5-10x=5</span>
D=(A19-A9)/(19-9)=(12,1-4,4)/10=0,77
A1=A9-8d=4,4-8*0,77=-1,76