Factorising -x2 + 7x + 18: (a - x)(x + b) = -x2 + (b - a)x + ab so ab = 18, b - a = 7 giving a = 2, b = 9: (2 - x)(x + 9)
x2-7x-18 (x-9) (x+2) x=9 x=-2 X= either 9 or -2
x2+7x-18 = (x-2)(x+9) when factored because -2*9 = -18 and 9x-2x = 7x
-(x - 9)(x + 2)
x2 + 7x = 2x2 + 6 x2 - 2x2 + 7x = 6 -x2 +7x - 6 = 0 or alternatively x2 - 7x + 6 = 0
x2-7x-18 = (x-9)(x+2) when factored
x2+7x-18 = (x+9)(x-2) when factored
The value of x2+7x+10 depends on the value of X. If x=1, then x2+7x+10 = 18 If x=2, then x2+7x+10 = 28 If x=3, then x2+7x+10 = 40 and so forth
Factorising -x2 + 7x + 18: (a - x)(x + b) = -x2 + (b - a)x + ab so ab = 18, b - a = 7 giving a = 2, b = 9: (2 - x)(x + 9)
x2-7x-18 (x-9) (x+2) x=9 x=-2 X= either 9 or -2
x2+7x-18 = (x-2)(x+9) when factored because -2*9 = -18 and 9x-2x = 7x
(x2 + 7x - 18) = (x + 9)(x - 2)
x^2 + 7x -18 = (x - 2)(x + 9)
x2 × 7x = 7x3
(x+2)(x-9)
-(x - 9)(x + 2)
x2 + 7x = 2x2 + 6 x2 - 2x2 + 7x = 6 -x2 +7x - 6 = 0 or alternatively x2 - 7x + 6 = 0