Answer:
The width of the garden bed must be less than or equal to 4 feet.

Explanation:
Given that;
She has 20 feet of boards to make the sides.
The perimeter of the garden bed must not be more than 20 feet

Given;
The length is 6 feet;

To get the inequality for the width w, let us substitute the value of the length into the inequality above and simplify;

Therefore, the width of the garden bed must be less than or equal to 4 feet.
4 as the denominator of the fraction is equal to the degree of the root so the answer is the 4th root of x
4(5x-20)=-20
20x-80=-20
20x=60
x=3
X + x + 2 + x + 4 = -213
3x + 6 = -213
3x = -219
x = -73
-73 + 2 = -71
-73 + 4 = -69
Solution: -73, -71, -69