Question 1114249
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Knowing how to solve the problem using formal algebra, as shown by the other tutor, is useful.  However, solving the problem by logical reasoning is excellent exercise for the brain.<br>
(1) The sum is 11 after decreasing it by 10.  So add the 10 back on; the sum of the two numbers is 21.<br>
(2) The sum of the two numbers is 21, and one is 9 more than twice the other.  Subtract that "extra" 9; now the sum of the two numbers is 12, and one of them is twice the other.<br>
(3) If the sum of the two numbers is 12 and one is twice the other, the numbers are 4 and 8.<br>
(4) Now add back on the 9 that you took away from the larger number.  The original numbers are 4 and 8+9=17.