Math 9
posted by Molly .
My family went to starbucks. We ordered 3 drinks. My daughter's drink was .90 cents less than my drink and my sons drink was $2.20 more than my drink. The total bill was $12.90. How much was each drink? Use algebra.
Please help me, thanx
sorry I had to repost this question. i really need help

Let x = parent's drink, then daughter's = x .90 and son's = x + 2.20.
x + (x.90) + (x+2.20) = 12.90
Solve for x.