x2 + 3x - 40 = x2 + 8x - 5x - 40 = x(x + 8) - 5(x + 8) = (x - 5)(x + 8)
Assume this quadratic equation equals zero. Then :-x2 - 13x + 40 = 0, this can be factored (x - 8)(x - 5) = 0This holds true when either x - 8 = 0 or x - 5 = 0When x - 8 = 0 then x = 8 : When x - 5 = 0 then x = 5
x2 + 8x = -15 x2 + 8x + 15 = 0 since 15 = 5 x 3 and 5 + 3 = 8, then (x + 5)(x + 3) = 0 x + 5 = 0 or x + 3 = 0 x = -5 or x = -3
If x = 8 then x2 = 82 = 8 x 8 = 64
x2+7x-8 = (x-1(x+8)
x2 + 3x - 40 = x2 + 8x - 5x - 40 = x(x + 8) - 5(x + 8) = (x - 5)(x + 8)
x2 + 13x + 40 = x2 + 5x + 8x + 40 = x(x + 5) + 8(x + 5) = (x + 8)(x + 5)
x2 + 3x - 40 = (x + 8)(x - 5)
Assume this quadratic equation equals zero. Then :-x2 - 13x + 40 = 0, this can be factored (x - 8)(x - 5) = 0This holds true when either x - 8 = 0 or x - 5 = 0When x - 8 = 0 then x = 8 : When x - 5 = 0 then x = 5
(x + 5)(x - 8)
x2 - 3x - 40 = (x - 8) (x + 5)
x2 + 8x = -15 x2 + 8x + 15 = 0 since 15 = 5 x 3 and 5 + 3 = 8, then (x + 5)(x + 3) = 0 x + 5 = 0 or x + 3 = 0 x = -5 or x = -3
If x = 8 then x2 = 82 = 8 x 8 = 64
X = 8 x2 (8)2 = 64 ====
x2+7x-8 = (x-1(x+8)
(x - 8)(x - 5)
11-x2=-5 add -11 to both sides: 11-x2-11=-5-11 -x2=-16 divide both sides by -2: (-x2)/(-2)=(-16)/(-2) x=8 If the "x2" was supposed to be "x2", meaning exponentiation, ("x squared") and not "x2", implying multiplication, ("x times two") then we'd get: x2=16 x=±4