-1x^2 + 7x + 18 = 0
-1(x^2-7x-18)=0
-1(x )(x ) ( -9)( +2)=0
-1(x-9) (x+2) = 0
Solve:
-1(x-9)=0
-1(x) (-1)(-9)=0
-1x+9=0
-1x+9-9=0-9
-1x=-9
-1x/-1=-9/-1
x=9
Solve:
-1(x+2) = 0
-1(x) (-1)(+2) = 0
-1x-2=0
-1x-2+2=0+2
-1x=2
-1x/-1=2/-1
x=-2