To isolate b, add a and subtract c to the entire equation:
D - a + c = -b
Muliply b by -1 to eliminate the negative:
-D + a - c = b
<span>A gallon of water weighs 8 1/3 lb
</span><span>1 1/5 gallon....................? lbs
</span>8 1/3 * 1 1/5
= 25/3 * 6/5
= 10
answer : <span>1 1/5 gallon of water weighs 10 lbs</span>
I may be wrong but i think the answer is 13.5
