1) -2х+1+5(х-2)=-4(3-х)+1
-2x+1+5x-10 = -12+4x+1
3x-9 = 4x-11
4x-3x = 11-9
x = 2
2) (х-5)^2 +(х+4)^2=2х^2
x^2-10x+25 +x^2+8x+16 = 2x^2
-2x+41= 2x^2 - 2x^2
2x = 41
x = 41/2
x =20,5
<span>3) 5+ х/2=3x+6/5
5+ 0,5x =3x +1,2
2,5x = 3,8
x = 3,8/2,5
x = 1,52</span>
0<= сos(кв) <=1 ; 0<=5cos(кв )<=5; -2<= 3-5cos(кв )<=3
1)-27x+5x=-220
22x=-220+x=10
2)7a-3a=310
5a=310
a=62
3)-2x-5x=-19-16
-7x=-35
x=5
4)-3b+5b=9-25
2b=-16
b=-8
Я написал сразу решение!