If we have 420 books for every 7 shelves and are looking for how many books are on 4 shelves, we need to set up fractional proportions.
We have 7 shelves for every 420 books, so we will have our first fraction like this:
7/420.
We also have 4 shelves for every x books, so our second fraction will be 4/x.
Set these fractions up as an equation.
7/420 = 4/x
To solve for x, we need to cross multiply the numerators of one fraction with the denominators of the other fraction.
In other words, multiply the top number of one fraction by the bottom number of the other question.
It should look like this:
7(x)
420(4)
7(x) = 7x
420(4) = 1680
Set your products up as an equation.
7x = 1680
Now to solve for x, we need to simplify.
Currently, x is being multiplied by 7.
To get x alone, divide 7x by 7.
Remember, what you do to one side of an equation, you must do to the other, so divide 1680 by 7.
7x / 7 = x
1680 / 7 = 240
You are left with:
x = 240.
For every 4 shelves you have 240 books.
I hope this helps!
Answer: The answer is 50
Step-by-step explanation:
I did the test
Answer:
Step-BYU-step explanation
4z - (-3z) = 4z + 3z = 7z
Since the cost of the telephone cost is 25 cents per minute, and by using the variable you provided, "t", the equation thus far is 25t=cost, or 25 multiplied by "t".
Since the telephone also charges 75 cents at the start, we just have to add it into our equation, making 75+25t=cost of telephone call in cents.
answer: 75+25t=cost of telephone call in cents
