Question

How to solve the equation 2x^2 -1 =5x?

Answer 1

x = 2.68, x = -0.186 is the answer , i got a 100% on my test

Explanation:

Answer 2

x = 2.68, x = -0.186

Explanation:

We are given the following equation that we are to solve:

`2 x ^ 2 - 1 = 5 x`

Rearranging this quadratic equation to get:

`2 x ^ 2 -5 x - 1 = 0`

Solving it by using the quadratic formula as we cannot find any factors for it.

`x= (-b \pm √(b^2-4ac) )/(2a)`

`x=(-(-5) \pm (-5)^2-4(2)(-1))/(2(2))`

`x=(5 \pm√(25+8) )/(4)`

`x=(5+√(33) )/(4)`,
`x=(5-√(33) )/(4)`

x = 2.68, x = -0.186