1) m² - n² - m + n = (m-n)*(m+n) - (m-n) = (m-n) * (m+n-1)
2) 9x² - 4y² - 3x + 2y = -(4y² - 9x²) - 3x + 2y = -(2y-3x) * (2y+3x) - 3x + 2y = (2y - 3x) * (1 - (2y+3x)) = (2y-3x) * (1-2y-3x)
3) x³ + 3x² - 4x - 12 = x² * (x+3)- 4 (x+3) = (x+3) * (x² - 4) = (x+3) * (x-2) * (x+2)
4) 81 - (3-8y)²=(9-(3-8у))(9+(3-8у))=(6+8у)(12-8У)
5) (x+5)²-16=(х+5-4)(х+5+4)=(х+1)(х+9)
6) 36-(y+1)²=(6-(у+1))(6+у+1)=(5-у)(7+у)
7) (3x-7)²-25=(3х-7-5)(3х-7+5)=(3х-12)(3х-2)=3*(х-4)(3х-2)
8) (4 - 5x)² - 64 = (4 - 5x)² - 8² = ( 4 - 5x - 8) ( 4 - 5x + 8) = ( - 4 - 5x) ( 12 - 5x) = - ( 4 + 5x) (12 - 5x)