Question

Разложите на множители : 

$1) a^{2} + 5a - b^{2} + 5b$ 

$2) p^{2} + 5p - 4q^{2} + 10q$ 

$3) 100m^{2} - 30m - 49n^{2} - 21n$ 

$4) 70m - 49m^{2} - 30n + 9n^{2}$ 

Answer 1

a^+5a-b^2+5b=(a^2+5a)-(b^2+5a)=a(a+5)-b(b-5)

и так же остальные

Answer 2

1. $a^2+5a-b^2+5b = (a-b)(a+b)+5(a+b) = (a+b)(a-b+5)$

2. $p^2+5p-4q^2+10q = (p-2q)(p+2q)+5(p+2q) = (p+2q)(p-2q+5)$

3. $100m^2-30m-49n^2-21n = (10m-7n)(10m+7n)-3(10m+7n) = (10m+7n)(10m-7n-3)$ 

4. $70m-49m^2-30n+9n^2 = 10(7m-3n)-(7m-3n)(7m+3n) = (7m-3n)(10-7m-3n)$