Question

Solve x(x - 2) = 4

Using quadratic formula

(Show step by step for the answer because I gotta show my work)

Answer 1

x = 1 ±
`√(5)`

Explanation:

x(x - 2) = 4

Multiply x on the left side by foil.

`x^(2)- 2x = 4`

Subtract 4 on both sides.

`x^(2) -2x-4=0`

Now, the quadratic formula.

x = (-b ±
`\sqrt{b^(2) - 4ac }`) / 2a

Using the standard form equation.

Ax² + Bx + C = 0

(1)x² - 2x - 4 = 0

A = 1

B = -2

C = -4

x = (-(-2) ±
`\sqrt{(-2)^(2)-4(1)(-4) }`) / 2(1)

x = (2 ±
`√(4+16)` ) / 2

x = (2±
`√(20)`)/2

x = (2±2
`√(5)`)/2

x = 1 ±
`√(5)`