Question 1187555
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Tom had 4/5 as many stamps as Michael. After Michael gave away 3/7 of his stamps, 
Tom had 40 more stamps than Michael. How many stamps did Tom have?
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<pre>
Let 5x be the number of stamps Michael had originally.

Then Tom had  4x stamps originally.


After Michael gave away 3/7 of his stamps, you have THIS equation


    {{{(4/7)*(5x)}}} = 4x - 40.


To solve, multiply both sides by 7.  You will get


    20x = 28x - 280

    280 = 28x - 20x

    280 =    8x

     x  = 280/8 = 35.


Tom had 4x = 4*35 = 140 stamps originally.    <U>ANSWER</U>
</pre>

Solved.


Notice that in my solution I introduced the unknown variable in a way to make my computations as simple as possible.