(X+3)(X-5) x=-3, 5

(X+4)(X+4) x=-4

(X+1)(X+1) x=-1

(X-7)(X+3) x=7, -3

(X+5)(X-4) x=-5, 4

(X-4)(X-2) x=2, 4

(x+3)(x-5) =0 [Factor]

Sovle: x+3 =0 OR x-5 =0

-3 -3 +5 +5

_______________________

x= -3 OR x = 5

15. x^2 + 2x + 1 = 0

(x+1)(x+1) = 0

Sovle: x+1 =0

-1 -1

_____________

x= -1 [same goes for the other side]

16. x^2 – 4x – 21 = 0

(x-7)(x+3) =0

Sovle: x-7=0 OR x+3=0

+7 +7 -3 -3

_________________________

x= 7 OR x= -3

17. x^2 + x – 20 = 0

(x-4)(x+5) =0

Sovle: x-4 =0 OR x+5=0

+4 +4 -5 -5

__________________________

x = 4 OR x = -5

18. x^2 – 6x + 8 = 0

(x-2)(x-4) =0

Sovle: x-2=0 OR x-4 =0

+2 +2 +4 +4

__________________________

x= 2 OR x=4

( x – 5) (x + 3) = 0

x = 5, -3

14. x^2 + 8x +16 = 0

(x + 4) (x + 4)

x = -4

15. x^2 + 2x + 1 = 0

(x + 1) (x + 1) = 0

x = -1

16. x^2 – 4x – 21 = 0

(x -7) (x + 3) = 0

x = 7, -3

17. x^2 + x – 20 = 0

(x + 5) (x – 4) = 0

x = -5, 4

18. x^2 – 6x + 8 = 0

(x – 4) (x -2) = 0

x = 4, 2

Hope this helps!

xx-2x=15

x-2=15

x=17

or are u supposed to do this

(x+3)(x-5)=0