Factor and solve: -1x^2 - 4x + 21 = 0

-1x^2 - 4x + 21 = 0

-1(x^2 + 4x - 21) = 0

-1(x-3) (x+7) = 0

Solve:

-1(x-3) =0

-1(x) (-1)(-3) =0

-1x+3=0

-1x+3-3=0-3

-1x=-3

-1x/-1=-3/-1

x=3

Solve:

-1 (x+7) = 0

-1 (x)(-1)(+7) = 0

-1x-7=0

-1x-7+7=0+7

-1x=7

-1x/-1=7/-1

x=-7