Question

What are the solutions of x2 + 8x − 20 = 0

Answer 1

This is a quadratic equation....there are several ways you can solve for x but note that you will have two values for x.

Answer 2

I think in this case we can complete the square

Answer 3

(x+a)(x+b)

a and b are two number that if you multiply them together you get -20
but if you add them you will get 8

Answer 4

(x+a)(x+b)=0

sorry I forgot to set it to zero

Answer 5

thanks

Answer 6

or it you just understand this at all you can always use the quadratic formula.
\[\begin{array}{*{20}c} {x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}} & {{\rm{when}}} & {ax^2 + bx + c = 0} \\ \end{array} \]
\[x^2 + 8x − 20 = 0\]

in this case

a=1
b=8
c=-20