From my understanding of mathematics I got the 2nd answer to be correct. Sorry, if I got this wrong I'm new at this.
The whole school would have 170 students that have a dog
Answer:
Second from top...
The average rate of change is $0.07, meaning that for each minute of talk time, the monthly bill increases by $0.07.
Step-by-step explanation:
Pick any two points and calculate the slope which will represent the rate of change:
(Minutes, Cost)
(0, 9.95)
(10, 10.65)
Rate of change:
slope m = (y₂ - y₁) / (x₂ - x₁)
= (10.65 - 9.95) / (10 - 0)
= 0.7 / 10
= 0.07
y is cost
m is rate of change
x is minute(s) use
b is fixed monthly cost regardless if any minutes is used
y = mx + b
y = .07x + 9.95
-6 and 4.5
So to do this you’ll make an equation x will represent the number so 4x^2+6x=108 so we want the equation to equal 0 so we can solve it to do that you have to subtract 108 from both sides so it ends up being 4x^2+6x-108=0 we want to isolate the x onto one side and division property allows us to divide both sides by 2 the reason it’s two is because 2 is the biggest divisible number that every number in the equation is divisible by so once you divide every number by two you get 2x^2+3x-54=0 now you have to factor cause but since you only have 3x and nothing else to factor with you have to write 3x as a difference so you could do 2x^2+12x-9x-54=0 so you are complicating the problem so you can factor out 2x from the expression so 2x(x+6)- 9(x+6)=0 the 54 got factored because it’s divisible by 9 that 6 is in replace of the 54 cause if you solved it 9x6 is still 54 next factor out x+6 so (x+6) x (2x-9) =0 so one of the two have to equal 0 so right the equations separately x+6=0 minus 6 from both sides and you’ll get x to equal -6 and 2x-9=0 add 9 to both sides and you’ll get 2x=9 divide both sides by 9 and you’ll get x to equal 4.5 when you plug 4.5 and -6 for x the equation works out
When you're looking for the volume of a cylinder, you have to use the equation

And this V is equal to volume, R is equal to radius, and H is equal to height.
In this case, you've got to find what r²is. To do this, square 5. 5x5= 25.
You've then got to substitute this into the equation, along side H, which is equal to 7, and this gives you V=π*25*7, you've then got to multiply these all together (using π as 3.142) this gives you 549.85cm³
Therefore, you need 549.85cm³ of water to fill the pipe.
Hope this helps :)