Hm, already some algebra for an elementary student. Huh.
Well anyway, onto the problem!
12/n
n represents the phrase "some number"
As n can be any number that solves the problem. Now we need it to equal 7. Because we want 12 divide by the number, n to equal 7.
12/n = 7
To solve this problem we need to solve for n. To do so we need it alone so the problem looks like this:
n = whatever the answer is.
To remove something from a problem you have to use something called the inverse operation. I'll go over them quickly.
Operation : Inverse Operation
Addition : Subtraction
Subtraction : Addition
Multiplication : Division
Division : Multiplication
There are a few more, but those will do for this problem!
12/n = 7
n is stuck in the denominator because it is dividing a number, so to remove it we simply multiply both sides by n.
12/n * n = 7n
12n/n = 7n
Now the n variables on the left will cancel out. (Because n/n = 1. Same as any number such as 9/9 equals 1. Or 4/4 equal 1. Or 100,000/100,000 equals 1).
12 = 7n
Divide 7 on both sides to get our answer!
12/7 = 7n/7
Same deal with the 7s. They will cancel out because they equal 1.
12/7 = n
Our answer is:
n = 12/7
12/(12/7) = 7
Let's check it!
When you divide something by a fraction you flip it and then multiply across. Like a so.
12*(7/12) = 7
(12*7)/12
The 12's will cancel out leaving us with 7.
7 = 7
It checks out!
