Combining the operations
The allowed operations are:
Add the same amount to both sides (either x's or ones)
Subtract the same amount from both sides (either x's or ones)
Multiply both sides by the same number (but not by zero)
Divide both sides by the same number (but not by zero)
(There are others, too, but they are not needed in simple equations.)
The goal is to FIRST add and subtract until we have ONLY x's (blocks) on one side and ONLY ones (circles) on the other. Then, if you have more than one block, you need to divide so as to arrive to the situation with only one block on the one side, which is the solved equation!
Answer:
x = 4
Step-by-step explanation:
I don't see a table but I can give you the means to answer it yourself. The inverse function is represented by this:

where k is your constant. You are given a k value of 4. If you solve this for k then you will get xy=4. In your tables, multiply your x value by your y value within your coordinate points and if you get a product of 4 each time you multiply x by y, then that table is your answer.
Round each coin weight to the nearest gram first, penny 3g, nickel 5g, dime 2g, quarter 6g, half dollar 11g. Now add those numbers together as he has one of each coin 3+5+2+6+11=27 grams