math
posted by alice on .
a coat,shirt and tie cost $300. coat costs twice as much as the shirt. shirt cost $40 more than twice the cost of the tie. what are the cost of each item?

30040=260

Let x = tie cost, then shirt = 2x+40 and coat = 2(2x+40).
x + (2x+40) + 2(2x+40) = 300
Get rid of parentheses and combine like terms.
x + 2x + 40 + 4x + 80 = 300
7x = 300120 = 180
Divide by 7.
x = 25.71
From there, calculate the shirt and coat.