Answer:
28 inches
Step-by-step explanation:
The three pieces are in the ratio
5:7:9
Multiply each piece by x
5x : 7x: 9x
Add the pieces together
5x+7x+9x = 147
Combine like terms
21x = 147
Divide each side by 21
21x/21 =147/21
x =7
The smallest piece is 5x = 5*7 =35
The largest piece is 9x = 9*7 =63
The difference is 63-35=28