-x2 = x - 6 x2 + x - 6 = 0 (x - 2)(x + 3) = 0 x ∈ {-3, 2}
x2 + x - 30 = (x + 6)(x - 5)
(x + 6)(x - 6)
x2 - x - 6 = (x - 3)(x + 2) = 0; whence, x = 3 or -2.
Strictly speaking, it is a quadratic equation in x. x2 + x = 6 => x2 + x - 6 = 0 => (x+3)*(x-2) = 0 => x = -3 or x = 2
x2 - 5x - 6 = x2 - 6x + x - 6 = x(x - 6) + 1(x - 6) = (x - 6)(x + 1)
-x2 = x - 6 x2 + x - 6 = 0 (x - 2)(x + 3) = 0 x ∈ {-3, 2}
8
x2 + x - 30 = (x + 6)(x - 5)
(x + 6)(x - 6)
x2 - x - 6 = (x - 3)(x + 2) = 0; whence, x = 3 or -2.
Strictly speaking, it is a quadratic equation in x. x2 + x = 6 => x2 + x - 6 = 0 => (x+3)*(x-2) = 0 => x = -3 or x = 2
x2 - 2x - 5 = 0 x2 - 2x + 1 = 6 (x - 1)2 = 6 x - 1 = ± √6 x = 1 ± √6
Given that 52 - x2 + x = 10, then -52 + x2 - x + 10 = x2 - x - 42 = (x - 7)(x + 6) = 0. Therefore, x = 7 or -6.
-4
x2 + 5x + 3 = 9 x2 + 5x - 6 = 0 (x + 6)(x - 1) = 0 x = -6 or x = 1
x = { +6, -6 }