1) (3х-1)(3х+1)+(3х+1)²=(3х+1)(3х-1+3х+1)=6х·(3х+1)
2)25а-ав²=а(25-в²)=а(5-а)(5+а)
3)х³-ху²-6у²+6х²=х(х²-у²)-6(у²-х²)=х(х²-у²)+6(х²-у²)=(х²-у²)(х+6)=(х-у)(х+у)(х+6)
Объяснение:
1) x12y6/x10y6*xy=x3y
2) x7y21*x18y12/x24y32=xy
3) x8/y8*x5y5/xy5=x12y-8
4) x5y8*x5y5/x10y6=x0y7=y7
2a во второй степени +18a-9