Folosind formula x²+(a+b)x+a×b=(x+a)(x+b),descomuneti in factori
a)x²-3x-10=
b)x²+x-12=
c)x²+4x-21=
2. Descompuneti in factori:
a) 4x²-4xy-8y²=
b)40x²+42x-49=