Calculati: a)3x(x+1)+(x-1)(x-2)=
b) (-√2x)²-2(x+1)(x-2)
c)(x+5)[(x-2)-2(x-3)
d)[(x+2)(2x-5)-x(2x-1)]ori(-3x)²
e)3(x²-2xy-y²)+2(x²+3xy+2y²)-(5x²+y²)