<PRE><B>Question 1138223</B>
&lt;br&gt;
4j+3c = 39
7j+2c = 39&lt;br&gt;
Solve the pair of linear equations by any method you choose.&lt;br&gt;
Here is a method you might not have seen that works very nicely for this problem.&lt;br&gt;
Continue the pattern shown by the two equations:
4j+3c = 39
7j+2c = 39  (3 more hours jogging and 1 less hour cycling gives the same total distance)
10j+c = 39  (continue the pattern of 3 more hours jogging and 1 less hour cycling)
13j = 39&lt;br&gt;
So j = 39/13 = 3; his jogging speed is 3km/hr.&lt;br&gt;
Then combining that with the first equation gives c = 9.&lt;br&gt;
ANSWER: jogging 3km/hr; cycling 9km/hr</PRE>