MAth
posted by Caroline .
I set this problem up as 5002X=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. ans1,300
5005002x=3,400500
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 = 2X500
Together, they earn
2X500 + X = 3400
3x = 3400 +500 = 3900
Can you take it from here?