How do you factor 50 + 5a - a^2, help I can't figure it out! I'm stuck?

(10 - a ) ( 5 + a )

50 + 5a - a² = 0
a² - 5/2a = 50 + (- 5/2)²
a² - 5/2a = 200/4 + 25/4
(a - 5/2)² = 225/4
a - 5/2 = ± 15/2

= a - 5/2 - 15/2, = a - 20/2, = a - 10
= a - 5/2 + 15/2, = a + 10/2, = a + 5

Answer: - ([a - 10][a + 5]) are the factors.

Proof:
= - ([a - 10][a + 5])
= - (a[a] + a[5] - 10[a] - 10[5])
= - (a² + 5a - 10a - 50)
= - (a² - 5a - 50)
= - a² + 5a + 50 rearrange to your original presentation
= 50 + 5a - a²

50 + 5a - a²
= -a² + 5a + 50
= -(a² - 5a - 50)
= -(a² - 10a + 5a - 50)
= -(a(a - 10) + 5(a - 10))
= -(a + 5)(a - 10)

50 + 5a - a^2
= -(-50 - 5a + a^2)
= -(a^2 - 5a - 50)
= -(a^2 + 5a - 10a - 50)
= -[(a^2 + 5a) - (10a + 50)]
= -[a(a + 5) - 10(a + 5)]
= -(a + 5)(a - 10)

Factorization:

50+5a -a^2 can be written as -a^2 +5a +50,

==> -a^2 +10a -5a +50,

==> -a(a -10) -5( a -10),

==> ( -a -5) (a - 10).

The two factors are : ( -a - 10) and (a - 10).

take out the negative
-(a^2 - 5a -50)
-(a -10)(a +5)

= 50 + 5a - a^2
= -a^2+5a+50

else use this -b(+or-)sqrt(b^2-4ac)/2a

we get....-5(+or-)sqrt(25+200)/-2

-5(+or-)15/-2

=-20/-2 or 10/-2

we get a=10 and a=-5