Question

If x*x+2x-35=0then x=?

Answer 1

`x^2+2x-35=0`
There are a few ways to solve this: factoring, completing the square, quadratic formula, among others.
I prefer to factor in most cases.
What factors of -35 add up to 2?
That would be -5 and 7. So, we can set the equation up like this:

`(x-5)(x+7)=0`
Now we can solve each of the expressions.

`x-5=0`

`x=5`
and

`x+7=0`

`x=-7`

Hope this helps!

Answer 2

x^2+2x-35=0 is of the form ax^2+bx+c

To factor you want to find two values, j and k, which satisfy two conditions:

ac=jk=-35 and b=j+k=2, so j and k must be 7 and -5.

Now replace bx with jx and kx in the original equation to get:

x^2+7x-5x-35=0 now factor 1st and 2nd pair of terms...

x(x+7)-5(x+7)=0 which is equal to:

(x-5)(x+7)=0

so x=-7 and 5