Answer:

Step-by-step explanation:
Given

Required
Determine the roots
To get the root of the function, then f(b) must be 0;
i.e. f(b) = 0
So, the expression becomes

Add 75 to both sides


Take square roots of both sides


Reorder

Expand 75 as a product of 25 and 3

Split the expression




The options are not clear enough; however the roots of the equation are 
Answer: 90
Step-by-step explanation:

Answer:
A. No real solution
B. 5 and -1.5
C. 5.5
Step-by-step explanation:
The quadratic formula is:
, with a being the x² term, b being the x term, and c being the constant.
Let's solve for a.



We can't take the square root of a negative number, so A has no real solution.
Let's do B now.





So B has two solutions of 5 and -1.5.
Now to C!




So c has one solution: 5.5
Hope this helped (and I'm sorry I'm late!)