David had 20 pencils.5 of them are green and 15 are purple.What percentage of pencils were green?
1 answer:
Answer: 25%
Step-by-step explanation: Since we know that David has 20 pencils in all and that 5 of the pencils he has are green, we have the fraction 5/20 which represents the 5 green pencils out of all of his pencils.
Now, remember the problem is looking for a percent so we need to write 5/20 as a percent in order to answer the question.
To write a fraction as a percent, first remember that a percent is a ratio of a number to 100. So to write 5/20 as a percent, we need to find a fraction equivalent to 5/20 that has a 100 in the denominator. We can do this by setting up a proportion.
Now, we can use cross products to find the missing value.
So we have 5 times 100 which is 500 <em>is equal</em> <em>to</em> 20 times n or 20n.
So we have 500 = 20n.
Now, dividing both sides of the equation by 20, we have <em>25 = n</em>.
So 5/20 is equal to 25/100 or 25%.
Therefore, 25% of David's pencils are green.
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Answer:
Choice A) x and f(x) approach negative infinity
Choice D) x and f(x) approach positive infinity
Step-by-step explanation:
A cubic curve starts low and ends high if the leading coefficient is positive, which in this case it is. This means that the left side of the graph falls while the right side rises. Your teacher might say something like "fall to the left, rise to the right" to describe what the end behavior is doing.
More formally "fall to the left" means that as x approaches negative infinity, y = f(x) is approaching negative infinity as well. Similarly, "rise to the right" indicates that as x approaches infinity, y = f(x) heads off to infinity as well. Both x and y = f(x) move in the same direction along their respective number lines; eg, if one goes in the negative direction, then so does the other.
The graph below confirms the answer visually.
