<PRE><B>Question 1151074</B>
&lt;br&gt;
(1) a typical solution using formal algebra....&lt;br&gt;
Huilan is 14 years older than Thomas:
t = Thomas&#39;s age
t+14 = Huilan&#39;s age&lt;br&gt;
The sum of their ages is 90:&lt;br&gt;
{{{(t)+(t+14) = 90}}}&lt;br&gt;
Solve using basic algebra....&lt;br&gt;
(2) Using much the same calculations, but informally....&lt;br&gt;
(a) Subtract 14 from Huilan&#39;s age; then the two are the same age, and the sum of their ages is 90-14 = 76.
(b) Divide by 2 to find that Thomas&#39;s age is 76/2 = 38.
(c) Add the 14 years back on to Huilan&#39;s age to find that his age is 38+14 = 52.&lt;br&gt;
ANSWER: Thomas is 38; Huilan is 52.&lt;br&gt;
Note that the problem only asks for Thomas&#39;s age, so we could stop after step (b).&lt;br&gt;
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