Efectuati :

a)(x^2+3x)(6x-3)-(5x-4)(3x^2+ x -7 )
b)(1-4x)(6x^2+5x)+(2x^2-3x+4)(x-5)
c)(8x+3)(2x-3x^2)-(3x^2+5x -2)(4-x)

Dau coroana si rezolvarea va rog !!!