Dave Bowers collects U.S. gold coins. He has a collection of 54 coins. Some are​ $10 coins, and the rest are​ $20 coins. If the face value of the coins is ​$780​, how many of each denomination does he​ have?

Answer 1

t for ten and w for twenty

t + w = 54

10 t + 20 w = 780

solve the system

Answer 2

10x +20y =780. X + y =54 . Solve simultaneously x=30 and y=24. . . If u wana knw hw many gold coin7 itz lyk dis 10 x 30=$300and 20 x 24 =$480

Answer 3

X = $10-coins.
54-x = $20-coins.

10x + 20(54-x) = 780.
10x + 1080 - 20x = 780.
-10x = -300.
X = 30.

54-x = 54-30 = 24