Answer:
0.4
Step-by-step explanation:
you just have to divide
2÷5=0.4
First of all, I'm going to assume that we have a concave down parabola, because the stream of water is subjected to gravity.
If we need the vertex to be at
, the equation will contain a
term.
If we start with
we have a parabola, concave down, with vertex at
and a maximum of 0.
So, if we add 7, we will translate the function vertically up 7 units, so that the new maximum will be 
We have

Now we only have to fix the fact that this parabola doesn't land at
, because our parabola is too "narrow". We can work on that by multiplying the squared parenthesis by a certain coefficient: we want

such that:
Plugging these values gets us

As you can see in the attached figure, the parabola we get satisfies all the requests.
First make and equation. Since you want to find the number of the day where both charge the same total amount, you would make the equation:
let x= the number of days
110+46(x)=70+54(x)
Solve:
110-70+46(x)=70-70+54(x)
40+46(x)=54(x)
40+46(x)-46(x)=54(x)-46(x)
40=8(x)
40/8=8x/8
5=x
Therefore your answer would be 5 days
Answer: A; 6.3%
Step-by-step explanation:
Problem 1
For the first problem, we first want to find y so that we can plug it into the expression.
We can use elimination method for the system of equations to solve.
3x+3y=21
3x-y=5
We subtract both equations to eliminate x.
4y=16 [divide both sides by 4]
y=4
Now that we know y, we can plug it into the expression.
[divide]
[subtract]

We know that the answer is A.
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Problem 2
For the second problem, we need to know how to calculate percent error. The formula for precent error is
. We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.
[subtract]
[solve absolue value]
[divide]
[multiply]

Since the problem said to round to one decimal place, we know that the answer is 6.3%.