Mister Exam

Factor polynomial x^2+x-20

An expression to simplify:

The solution

You have entered [src]
 2         
x  + x - 20
$$\left(x^{2} + x\right) - 20$$
x^2 + x - 20
The perfect square
Let's highlight the perfect square of the square three-member
$$\left(x^{2} + x\right) - 20$$
To do this, let's use the formula
$$a x^{2} + b x + c = a \left(m + x\right)^{2} + n$$
where
$$m = \frac{b}{2 a}$$
$$n = \frac{4 a c - b^{2}}{4 a}$$
In this case
$$a = 1$$
$$b = 1$$
$$c = -20$$
Then
$$m = \frac{1}{2}$$
$$n = - \frac{81}{4}$$
So,
$$\left(x + \frac{1}{2}\right)^{2} - \frac{81}{4}$$
General simplification [src]
           2
-20 + x + x 
$$x^{2} + x - 20$$
-20 + x + x^2
Factorization [src]
(x + 5)*(x - 4)
$$\left(x - 4\right) \left(x + 5\right)$$
(x + 5)*(x - 4)
Common denominator [src]
           2
-20 + x + x 
$$x^{2} + x - 20$$
-20 + x + x^2
Powers [src]
           2
-20 + x + x 
$$x^{2} + x - 20$$
-20 + x + x^2
Combinatorics [src]
(-4 + x)*(5 + x)
$$\left(x - 4\right) \left(x + 5\right)$$
(-4 + x)*(5 + x)
Numerical answer [src]
-20.0 + x + x^2
-20.0 + x + x^2
Rational denominator [src]
           2
-20 + x + x 
$$x^{2} + x - 20$$
-20 + x + x^2
Assemble expression [src]
           2
-20 + x + x 
$$x^{2} + x - 20$$
-20 + x + x^2
Trigonometric part [src]
           2
-20 + x + x 
$$x^{2} + x - 20$$
-20 + x + x^2
Combining rational expressions [src]
-20 + x*(1 + x)
$$x \left(x + 1\right) - 20$$
-20 + x*(1 + x)