Jim weighs 30 pounds less than Tom, and together they weigh 210 pounds. Let nn Tom's weight in pounds. What would be the equation that expresses the total of Jim's and Tom's weights?

1 Answer
Mar 29, 2018

Jim and Tom's total weight is expressed by

n+(n-30)=210n+(n30)=210

and solving this equation tells us that Tom weighs 120 pounds, and Jim weighs 90 pounds.

Explanation:

If nn is Tom's weight, then Jim's weight is

n-30n30

So an equation for their total weight would be

n+(n-30)=210n+(n30)=210

We could then continue to solve for nn to find Tom's weight

rArr2n-30=2102n30=210

rArr2n-cancel30 color(red)(+cancel30)=210 color(red)(+30)

rArr2n=240

rArr(cancel2n)/color(red)cancel2=240/color(red)2

rArrn=120

Tom weighs 120 pounds.

Jim's weight is then

n-30

rArrcolor(red)120-30

rArr90

Jim weighs 90 pounds.