Factor the polynomials completely. if the polynomial cannot be factored, write "prime." 4) 144-m^2 5) y^2+24y+144 6) x^4-625 7) 7(a+9)-y(a+9) 8) x^2 +25 9) y^2-4y-77

4) -(m+12)(m-12)

5) (y+12)^2

6) (x+5)(x-5)(x^2-25)

7) (a+9)(-y+7)

8) Prime

9) Prime

Hope this helps!

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm