Answer:
10 blocks.
Step-by-step explanation:
Find the unit rate.

Therefore, 10 blocks weigh 70 ounces.
 
        
                    
             
        
        
        
It's just asking for the gradient basically
150/3 = 50
Or technically -50 because it's decreasing
        
             
        
        
        
Make f(x) = y
y = (15x + 50)/(x + 5)
Swap the x and y and make y the subject again 
x = (15y + 50)/(y + 5)
x(y + 5) = 15y + 50
xy + 5x = 15y + 50
xy - 15y = 50 - 5x
y(x - 15) = 50 - 5x
y = (50 - 5x)/(x - 15)
So inverse function f^-1(x) = (50 - 5x)/(x - 15)
        
             
        
        
        
The Quadratic<span> Formula uses the "a", "b", and "c" from "ax</span>2<span> + bx + c", where "a", "b", and "c" are just numbers; they are the "numerical coefficients" of the </span><span>quadratic equation. Therefore, 
</span><span>f(x) = x2 – 5x + 6
a = 1
b = -5
c = 6</span>