Answer:

Step-by-step explanation:
Remember:
![(\sqrt[n]{a})^n=a\\\\(a+b)=a^2+2ab+b^2](https://tex.z-dn.net/?f=%28%5Csqrt%5Bn%5D%7Ba%7D%29%5En%3Da%5C%5C%5C%5C%28a%2Bb%29%3Da%5E2%2B2ab%2Bb%5E2)
Given the equation
, you need to solve for the variable "x" to find its value.
You need to square both sides of the equation:


Simplifying, you get:

Factor the quadratic equation. Find two numbers whose sum be 7 and whose product be -8. These are: -1 and 8:

Then:

Let's check if the first solution is correct:

(It checks)
Let's check if the second solution is correct:

(It does not checks)
Therefore, the solution is:

By iteratively substituting, we have



and the pattern continues down to the first term
,



Recall the formulas


It follows that



If you put 0 in the place of x or y, which every one you choose, it will cancel it or and you can just divide the number next to it by the answer (-20, 20). Take it one step at a time, don't try to do both at the same time.
Note that h(x) = 4x^2 - 8x - 60 factors to 4(x^2 - 2x - 15), and that the roots (zeros) of (x^2 - 2x - 15) are -5 and +3. Thus, the smallest zero is -5.