Question

Factor completely 9-6a-24a^2

Answer 1

-24a²- 6a +9 = - 3(8a² +6a - 9)

8a² +6a - 9 =0

x=(-b +/-√(b² - 4ac))/2a
x = (-6 +/-√(36+4*8*9)  /(2*8) = (-6 +/-√(324)  /16 =  (-6 +/-18)/16
x1 =  (-6 +18)/16 = 0.75
x2 =  (-6 -18)/16 = - 1.5

-24a²- 6a +9 = - 3(8a² +6a - 9) = -3(a - 0.75)(a + 1.5)

Answer 2

-3 (2a - 1) (4a + 3)