Question

РЕШИТЕ ПЛЗ!!! 30 БАЛЛОВ Versia 2

Answer 1

y² - 9y + 20 = (y - 5)(y - 4)

p³ - 7p² - 21p + 27 = (p³ + 27) - (7p² + 21p) = (p + 3)(p² - 3p + 9) - 7p(p + 3) =

= (p + 3)(p² - 3p + 9 - 7p) = (p + 3)(p² - 10p + 9) = (p + 3)(p - 1)(p - 9)

9x² + 9ax² - y² + ay² + 6axy = (9x² - y²) + (9ax² + ay² + 6axy) =

= (3x + y)(3x - y) + a(9x² + 6xy + y²) = (3x + y)(3x - y) + a(3x + y)² =

= (3x + y)(3x - y + 3ax + ay)

$\frac{25y^{2}-20y-9z^{2}+4}{25y^{2} -30yz+9z^{2} -4}=\frac{(25y^{2}-20y+4)-9z^{2} }{(25y^{2}-30yz+9z^{2})-4}=\frac{(5y-2)^{2}-9z^{2}}{(5y-3z)^{2}-4 }=\frac{(5y-2-3z)(5y-2+3z)}{(5y-3z-2)(5y-3z+2)}=\frac{5y+3z-2}{5y-3z+2}$

$\frac{27-15a+5a^{2}-a^{3}}{3a+ab-3b-a^{2}}=\frac{(27-a^{3})+(5a^{2}-15a)}{(3a-3b)+(ab-a^{2})}=\frac{(3-a)(9+3a+a^{2})+5a(a-3) }{3(a-b)+a(b-a)}=\frac{(3-a)(9+3a+a^{2})-5a(3-a) }{3(a-b)-a(a-b)}=\frac{(3-a)(9+3a+a^{2}-5a)}{(a-b)(3-a)}=\frac{a^{2}-2a+9}{a-b}$