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MAXImum [283]
3 years ago
7

Barbara answered 72 questions correctly on her test. If her score on the test was 80%, how many questions were on the test?

Mathematics
2 answers:
Pani-rosa [81]3 years ago
5 0
Answer is B - 90
-----
elena55 [62]3 years ago
5 0
For a percentage question setup is like this:
part = percentage * whole

part = 72
percentage = 80% = 0.8

72 = 0.8 * whole
whole = 72/0.8 = 90
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An artist can paint 4 paintings in 2 hours. What is this artists unit rate?
koban [17]
The unit rate is 2 paintings per hour.
4 0
3 years ago
The average value of a function f over the interval [−2,3] is −6 , and the average value of f over the interval [3,5] is 20. Wha
Xelga [282]

Answer:

The average value of f over the interval [-2,5] is \frac{10}{7}.

Step-by-step explanation:

Let suppose that function f is continuous and integrable in the given intervals, by integral definition of average we have that:

\frac{1}{3-(-2)} \int\limits^{3}_{-2} {f(x)} \, dx = -6 (1)

\frac{1}{5-3} \int\limits^{5}_{3} {f(x)} \, dx = 20 (2)

By Fundamental Theorems of Calculus we expand both expressions:

\frac{F(3)-F(-2)}{3-(-2)} = -6

F(3) - F(-2) = -30 (1b)

\frac{F(5)-F(3)}{5-3} = 20

F(5) - F(3) = 40 (2b)

We obtain the average value of f over the interval [-2, 5] by algebraic handling:

F(5) - F(3) +[F(3)-F(-2)] = 40 + (-30)

F(5) - F(-2) = 10

\frac{F(5)-F(-2)}{5-(-2)} = \frac{10}{5-(-2)}

\bar f = \frac{10}{7}

The average value of f over the interval [-2,5] is \frac{10}{7}.

4 0
3 years ago
A rectangular, above-ground swimming
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The answer is A. 158 lbs
3 0
3 years ago
What number must you add to complete the square x^-8x=39
notsponge [240]

Answer:

Given equation: x^2-8x =39

when we complete the square , we take half of the value of 8 , then square it, and added to the left sides, we get;

x^2-8x+4^2 = 39 +4^2

∵8 is the value (\frac{8}{2})^2

Notice that, we add this both sides so that it maintains the equality.

then;

x^2-8x+4^2 = 39 +4^2

(x-4)^2 = 39 + 16   [ (a-b)^2 = a^2-2ab+b^2 ]

Simplify:

(x-4)^2 =55

The number must be added to complete the square is, 4^2 = 16



3 0
3 years ago
Read 2 more answers
A number is multiplied by 5. If 12 is added to the product you get 37.
Korolek [52]


5x+12=37

5x=25

x=5

I hope this helps


5 0
4 years ago
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