For what value
K is the following system consistent?
(i) p+q=6
(ii) kp+q=18
(iii) p+kq=30
Source: Terry Stickel, Challenging Math Problems, 2015
(k+1)(p+q) = 48 from ii and iii
6(k+1) = 48 by substitution from i
k+1 = 8
k=7 ... the answer
p=2 and q=4 are the other two values.

Posted by Charlie
on 20190130 11:38:01 