# Jacquez knows 5 x n but doesn't know 7 x n. Explain to Jacquez how he could use his known fact to to solve for an unknown fact. Include an example to help Jacquez understand.

Jacquez has two equations:

`5*n=X`

`7*n=Y`

He knows the value of X, but not Y. Jacquez can use the first equation to solve for the value of n. Then, he can plug the value for n into the second equation in order to find the value of Y.

Let's say Jacquez is given the following example:

We will choose X = 35 for this example, although you could use any number you like.

`5*n=35`

`7*n=Y`

In this example, both n and Y represent unknown quantities. Now, using the first equation, we solve for the value of n.

`n = 35/5 = 7`

Then we plug n = 7 into the second equation to solve for Y.

`7*n=Y=7*7=49`

This was an example of a problem with two equations and two unknowns (n and Y). As long as the number of equations is at least equal to the number of unknowns, you can solve the problem.

Approved by eNotes Editorial Team