In order to answer this question, we must break this mathematical expression up into a series of mathematical operations (exponent, multiplication,division, addition, and/or subtraction):
"4 times a number" - The word "times" implies that we have to multiply 4 by an unknown number. We can simply label this unknown number as x.
"cubed" - In order to "cube" a number, we must raise it to the third power, or have an exponent of 3. Our unknown number of x now becomes x3 because we raised it to the third power.
"decreased by 7" - The word "decreased" implies that we must subtract 7 from the product of 4 multiplied by x3
With all of the information we now have, we can form an algebraic expression for this problem.
"4 times a number cubed decreased by 3" now becomes:
4x3 - 7
Answer:
1.b
2.d
Step-by-step explanation:
i think
Independent variable = number of cars with domain 30 to 100 cars
Dependent variable = money raised with range $600 to $2000
(x cookies) / (23 students - (12/2) students) = 2 cookies per student
[x / (23 - 6)] cookies per student = 2 cookies per student
23 students * (2 cookies per students) - 12 cookies = x cookies
The "students" unit cancels
46 cookies - 12 cookies = x cookies
x cookies = 34 cookies
Answer:
as written: 2500.2
as intended: 3000
Step-by-step explanation:
20% = 0.2, so adding 0.2 to 2500 gives 2500.2
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We suspect you want to add 20% of 2500 to 2500. That is ...
2500 + 20%×2500
= 2500 + 0.20×2500
= 2500 + 500
= 3000
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<em>Comment on percentages</em>
A percentage is a pure number. It is a ratio of like quantities, so has no units.* A <em>useful</em> percentage always has a base. That is, it is a percentage <em>of something</em>. Sometimes that base may be unclear or unstated, in which case the percentage might very well be considered to be meaningless.
In any event, a percentage is simply a (unitless) fraction. The "%" symbol means the same thing as "/100", so 20% means 20/100 = 2/10 = 1/5.
The very clear math expression 2500 +20% means simply 2500 + 1/5, which is the mixed number 2500 1/5 or the decimal value 2500.2. Usually, when we want to add a percentage to some value, we want the percentage to be <em>of the original value</em>. When that is written as a math expression, it must show this:
2500 + 20% of 2500
2500 + 20%×2500
2500(1 +20%)
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* The concentration or potency of some medicines or other mixtures may be expressed as a percentage that is the ratio of one unit to a different unit, typically weight per volume. That is, a "0.1%" preparation may be 0.1 grams per 100 mL, for example. You have to read the label to determine whether this is the case. Mathematically, this is not a percentage, but is a non-standard use of the "%" symbol to indicate a ratio to 100 of something.
