<human>:  Rodney, Roger and Ron can lift a combined weight of 239 pounds. Rodney can lift twice as much as Roger, and Roger can lift 7 pounds less than 4 times the amount that Ron can lift. How much can Rodney lift?
<bot>: Define a variable ** Let x represent the amount that Ron can lift.
How many pounds can Roger lift? ** Roger: 4x-7
How many pounds can Rodney lift? ** Rodney:2(4x-7)=8x-14
Write an equation ** Total:x+4x-7+8x-14=239
Combine like terms ** 13x-21=239
Add 21 to both sides ** 13x=260
Divide by 13 ** x=<<20=20>>20
How many pounds can Rodney lift? ** Rodney:8(20)-14=146 pounds
#### 146