Amy, Bruce and Carlos collected a total of 168 pounds of cans to recycle. Bruce collected 1/3 the number of pounds of cans Carlos collected. Amy collected the same number of pounds of cans as Bruce and Carlos combined. Let c represent the number of pounds of cans Carlos collected. Write an equation, in terms of c, that expression the relationship between the number of pounds of can collected by each student and the total weight of the cans collected.
I just need help setting up an equation. I already found out what they each collected.

a + b + c = 168
b = 1/3c
a = b + c....a = 1/3c + c = 4/3c

now we sub
4/3c + 1/3c + c = 168
8/3c = 168
c = 168 * 3/8
c = 504/8
c = 63 <=== Carlos collected 63 lbs

a = 4/3c
a = 4/3(63)
a = 252/3
a = 84 <== Amy collected 84 lbs

b = 1/3c
b = 1/3(63)
b = 63/3 <== Bruce collected 21 lbs
b = 21

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