а) 1,5(2x-3)+0,2(7-3x)=
= 3x - 4,5 + 1,4 - 0,6x =
= 2,4x -3,1
б) (3a-1)(3a+1)-6a2=
=9a^2-1 - 6a^2 = 3a^2-1
в) (c+2)(c2-2c+4)=
= c^3-2c^2+4c + 2c^2 - 4c +8 =
= c^3 + 8
a) 3-4(1-6x)=2(3x+4)
3-4 + 24x = 6x + 8
24x-6x = 8-3+4
18x = 9
x = 9:18
x=9/18 = 1/2