Rezolvati urmatoarele exercitii folosind factorul comun :
a) (x-6)•(x-6)+(x+1)(x-6)•(x-6)-(5-3x)(x-6)
b) (4x-5y)(2x+y)-(3x-y)(5y-4x)+(5y-4x)(5y-4x)
C) (2x+3y)(2x+3y)(x-y)+3(2x+3y) la a treia - 2(3x+4y)(3y+2x) la a doua