Question

Solve for x. Round your answers to two decimal places.

solve for x
2x^2 + 6x = 4

x = −0.56 and x = 3.56
x = 0.56 and x = −3.56
x = −0.40 and x = 2.90
x = 0.40 and x = −2.90

Answer 1

x = 0.56 and x = -3.56

Explanation:

`2x^(2) +6x=4`

We can use a formula to solve for x called the quadratic formula.

Quadratic formula:
`x=(-b+-√(b^2-4ac) )/(2a)`

First we need to write the equation in standard form

`2x^(2) +6x = 4` ⇒
`2x^(2) +6x-4=0`

Where a = 2, b = 6 and c = -4

Now we're ready to solve for x using the quadratic formula!

`x=(-b+-√(b^2-4ac) )/(2a)`

`x=(-6+-√(6^2-4(2)(-4)) )/(2(2))`

`x=(-6+-√(68) )/(4)`

`x=(-3+-√(17) )/(2)`

`x=(-3+√(17) )/(2) =0.56`
`x=(-3-√(17) )/(2) =-3.56`

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*Btw the +- sign means ± just it doesn't let me type it with the math fonts*