0.5x³ = 2-x
0.5x³-x = 2
x(0.5x²-1) = 2
x=0 или 0.5x²-1=0
0.5x²=1
x²=2
x=√2
2(a-3)^2= 2(a^2-6a+9)=2a^2-12a+18
3(x+y)^2=3(x^2+2xy+y^2)=3x^2+6xy+3Y^2
-5(1-2c)^2=-5(1-4c+4c^2)=-5+20c-20c^2
остальное аналогично
В)15-5(1-а)-6а =15-5+5а-6а =10-а
г) 4y-(3y-(2y-1))=4y-(3y-2y+1)=4y-3y+2y-1=3y-1