x2 - 4
x2 - 6x - 16 = (x - 8)(x + 2)
-x2 + 6x + 16 = -(x2 - 6x - 16) = -(x - 8)(x + 2) = -(8 - x)(x + 2)
16 + 6x - x2 = 16 + 8x - 2x - x2 = 8*(2 + x) - x*(2 + x) = (8 - x)*(2 + x)
x2 - 6x = 16 ∴ x2 - 6x + 9 = 25 ∴ (x - 3)2 = 25 ∴ x - 3 = 25 ∴ x = 28
X2 - 16(X - 4)(X + 4)============X2 + 16===========not factorable in real numbers
Given: x2 + 10x - 16 Let: x2 + 10x - 16 = 0 x2 + 10x - 16 = 0 ∴ x2 + 10x + 25 = 16 + 25 ∴ (x + 5)2 = 41 ∴ x = -5 ± √41 ∴ x2 + 10x - 16 = (x + 5 + √41)(x + 5 - √41)
x2 - 4
x2 - 6x - 16 = (x - 8)(x + 2)
-x2 + 6x + 16 = -(x2 - 6x - 16) = -(x - 8)(x + 2) = -(8 - x)(x + 2)
x2 + 6x = 16=> x2 + 6x - 16 = 0=> x2 + 8x -2x - 16 = 0=> (x+8)(x-2) = 0=> x = -8 or x = 2So, the solutions of the quadratic equation x2 + 6x = 16 are -8 and 2.
X2 + 8x + 16 = 10x +16x2 + 8x + 16=2x + 8x + 16=10x + 16
if x2 ≠ 16, then: {x | x ∈ ℜ, x ∉ (4, -4)}
x2 - 16 = (x + 4)(x - 4) x2 - 16 is the difference of two squares: a2 - b2 factorises as (a + b)(a -b), thus: x2 - 16 = x2 - 42 = (x + 4)(x - 4)
264
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
16 + 6x - x2 = 16 + 8x - 2x - x2 = 8*(2 + x) - x*(2 + x) = (8 - x)*(2 + x)