Julia paid $640 for 5 shirts and 2 pair of pants. If she bought another shirt, she would have $30 left. If she bought another pair of pants, she would be short of $10. How much did Julia have?

Let's denote the price of a shirt as S and the price of a pair of pants as P.

From the problem, we know that:

5S + 2P = $640 (This is the amount Julia paid for 5 shirts and 2 pairs of pants)

We also know that if Julia bought another shirt, she would have $30 left. This means that the price of a shirt plus$30 is equal to the total amount of money Julia had. We can write this as:

S + $30 = Total Amount Julia Had

Similarly, if Julia bought another pair of pants, she would be short of $10. This means that the price of a pair of pants minus$10 is equal to the total amount of money Julia had. We can write this as:

P - $10 = Total Amount Julia Had

Now we have a system of three equations, and we can solve it to find the total amount of money Julia had.

First, let's solve the second and third equations for the Total Amount Julia Had:

S + $30 = P -$10

This gives us:

S - P = -$40

Now we can substitute S - P = -$40 into the first equation:

5S + 2P = $640 becomes 5(S - P) + 7P =$640

This simplifies to:

5(-$40) + 7P =$640

-$200 + 7P =$640

7P = $840

P = $120

Substitute P = $120 into S - P = -$40:

S - $120 = -$40

S = $80

Finally, substitute S = $80 into S +$30 = Total Amount Julia Had:

$80 +$30 = Total Amount Julia Had

Total Amount Julia Had = $110

So, Julia had $110.