# How do you solve #30 + x − x^2 = 0#?

##### 3 Answers

#### Explanation:

Invert (multiply by -1, has the same solutions) and complete the square:

Solve for

=>

=>

solve

Ans: -5 and 6

#### Explanation:

I use the new Transforming Method (Google, Yahoo, Bing Search)

Find 2 numbers knowing sum (1) and product (-30). Roots have opposite signs since a and c have opposite signs.

Factor pairs of (-30) --> (-2, 15)(-4, 5)(-5, 6). This sum is 1 = b.

Since a < 0. then the 2 real roots are: -5 and 6.

You could use the *quadratic formula*.

#### Explanation:

First, rewrite your quadratic in the form

for which the *quadratic formula* takes the form

You will start from

which can be rewritten as

In this case,

The two solutions to this quadratic equation will thus be