Answer:
-2 
Step-by-step explanation:
First, you need to find the equation. 
f(x) = -3x + b
Now we need to find the y-intercept. 
f(x) = -3x + b
f(-9) = -3(1) + b
-9 = -3 + b 
-6 = b 
f(x) = -3x - 6
The zero of f means that f(x) = 0
 f(0) = -3x - 6
f(6) = -3x 
x = -2 
 
        
             
        
        
        
Answer:
y=17
Step-by-step explanation:4(y+8)=100
We move all terms to the left:
4(y+8)-(100)=0
We multiply parentheses
4y+32-100=0
We add all the numbers together, and all the variables
4y-68=0
We move all terms containing y to the left, all other terms to the right
4y=68
y=68/4
y=17
    
 
        
                    
             
        
        
        
This is a 3 step problem. First you ignore the hole in the middle and find the volume anyways. Then you find the volume of the empty middle part. Then you can find the volume of the actual shape by subtracting them. 
area of a circle is= pi r^2
Volume with hole: 5*5*pi*8=200pi
Volume of hole= 1.5*1.5*pi*8= 18pi
Volume of doughnut = 200pi-18pi=182pi=571.769863u^3
r is the radius which is half of the diameter. 
pi is a big number but you can use 3.14
the formula for finding the volume is area of base times height. That's why i multiplied it by 8.]
I hope this helps