1.а) 3(х+1)²-6х=3(х²+2х+1)-6х=3х²+6х+3-6х= 3х²+3=3(х²+1)
б)(5х+1)(3х+4)-23(х-2)=6х²+20х+3х+4-23х+24=6х²+50
в)(3х²+1)+(х²-3)=9х∧4+6х²+1+х∧4-6х²=9=10х∧4+10
г)(зх+4)²-(2х-3)(2х+3)=9х²+24х+16-4х²-9=5х²+24х+7
2. а) 9х²-6х+у²=(3х-у)²
г)(а²-а)-(b²-1)=a(a-1)-b(b-1)
д)x³c²-x³d²=x³(c²-d²)=x³(c-d)(c+d)
e)-3a²-6ab-3b²= -3(a²+2ab+b²)= -3(a+b)²