Question

How do you solve `4p^2=-25p-25` using the quadratic formula?

Answer 1

`-5 or (-5)/4`

Explanation:

To use the quadratic formula our function has to be in the form:

`a^2 + bx +c =0`

So, let's start off by subtracting `4p^2` from both sides, to get it into that form. That gives us:

`0 = -4p^2 -25p - 25`

I'm also going to multiply both sides by `-1`, to eliminate all of the negatives. You don't have to do this, but it will make the process quite a bit cleaner. That leaves us with:

`0 = 4p^2 +25p + 25`

So, `a = 4`, `b=25`, `c=25`

Now we simply substitute our values into the quadratic equation

= `(-b+-sqrt(b^2-4ac))/(2a)`

= `(-(25)+-sqrt((25)^2-4(4)(25)))/(2(4))`

= `(-25+-sqrt(225))/(8)`

= `(-25+-15)/(8)`

= `(-40)/(8) or (-10)/8`

= `-5 or (-5)/4`