The proportion that could be used to solve for the variable is:
; p = 12 ⇒ b
Step-by-step explanation:
Direct proportion means that two (or more) quantities increase or decrease in the same ratio
- y = k x is the equation of direct proportion, where k is the constant of proportionality
is the another way to write a proportion
The number of pencils and the cost of them is increased together or decreased together
∴ The number of the pencils and their costs are in direct proportion
- By using the 2nd rule above
∵ The cost of the 7 pencils is $1.68
∵ The cost of p pencils is $2.88
∴ 
The proportion that could be used to solve for the variable is: 
∵ 
- By using cross multiplication
∴ p × 1.68 = 7 × 2.88
∴ 1.68 p = 20.16
- Divide both sides by 1.68
∴ p = 12
The value of variable p is 12
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"x = 2; a = 5; b = 3" A 5 inch tall bamboo shoot doubles in height every 3 days. If the equation y=ab^x, where x is the number of doubling periods, represents the height of the bamboo shoot.
Set the expressions equal to each other to get 17
Answer: The required value of f(3) is 81.
Step-by-step explanation: We are given the following function :

We are to find the value of f(3).
Substituting x = 3 in equation (i), we get

Thus, the required value of f(3) is 81.
Answer:

Step-by-step explanation:
Given that,

We need to find the value of cos x.
We know that,

Using the above relation,

So, the value of cos x is equal to
.