Hello Jesse,

Let's call those two numbers x and y. We will "translate" the information given to us into equations.

"the difference of 2 numbers is 90" -----> **x - y = 90**

"and their quotient is 10" -------> **x/y = 10**

Now you have a system of two equations:

**x - y = 90**

**x/y = 10**

You can solve it a few ways. Let's use substitution. We will rewrite the 2nd equation as x in terms of y, then substitute x in the 1st equation:

Rewriting the 2nd equation gives us: x = 10*y

Now in the first equation, replace x by 10*y. That is substitution -----> 10y - y = 90 ----> 9y = 90 ----> **y = 10**

See how substitution gets you an equation where you can easily solve one variable?

Now that know **y = 10**, you can plug 10 into any of the 2 equations of your system. If you choose the 1st equation:

**x - 10 = 90**

I will let you solve this simple equation.

Cheers!

Ausin P.

So what’s the answer?18d