I set this problem up as 500-2X=3,400

Marys monthly salary is $500 less than twice her daughter's salary. Together they earn $3,400 each month. How much is the daughter's salary. ans-1,300
500-500-2x=3,400-500
2x=3,100
2x/2=3,100/2
what am I missing

You're close, here's what you could have done:

daughter's salary = X
Mary's salary = 2X-500

Together, they earn
2X-500 + X = 3400
3x = 3400 +500 = 3900

Can you take it from here?

You are on the right track, but you made a small mistake in your calculations. Let's go through the steps again to find the correct answer:

1. Start with the equation: 500 - 2x = 3,400.
This equation represents the statement "Mary's monthly salary is $500 less than twice her daughter's salary, and together they earn $3,400 each month."

2. Simplify the equation by subtracting 500 from both sides:
500 - 500 - 2x = 3,400 - 500.
This simplifies to:
-2x = 2,900.

3. Now divide both sides of the equation by -2 to solve for x:
-2x / -2 = 2,900 / -2.
This gives us:
x = -1,450.

However, it's impossible for the daughter's salary to be negative. So, it seems there was an error earlier.

If we examine the original equation:

500 - 2x = 3,400,

we can see that Mary's monthly salary is $500 less than twice her daughter's salary. This means that we need to find the daughter's salary. Let's solve for x again:

1. Start with the equation: 500 - 2x = 3,400.

2. Subtract 500 from both sides of the equation:
-2x = 3,400 - 500.

3. Simplify the equation:
-2x = 2,900.

4. Divide both sides of the equation by -2 to solve for x:
x = 2,900 / -2.

Dividing 2,900 by -2 gives us:
x = -1,450.

So the daughter's salary seems to be $-1,450 according to the equation, but that doesn't make sense in a real-world context. Therefore, there might be an error in the initial problem setup or the given answer.