Dave is three times older than jim, and jim is half bill’s age. if their average age is 64, what is jim’s age?

d = 3j

j = 1/2b

64 = (d + j + b)/3

d = 3(1/2b)

d = 1.5b

64 = (1.5b + 1/2b + b)/3

Combine like terms.

64 = (3b)/3

Multiply both sides by 3.

192 = 3b

Divide both sides by 3.

64 = b

Because we have the value for b we can plug it into the other equations to solve for the other ages.

j = 1/2b

j = 1/2(64)

j = 32

d = 3j

d = 3(32)

d = 96

it is 28 degrees colder in detroit than philadelphia.

step-by-step explanation:

what number adds to 21

-7 + ? = 21

-7 + 28 = 21

hope it