Question 137884
The tens digit of a two-digit number is 1 less than five times the units digit. The square of the units digit is 5 less than the tens digit. Find the number. 
have tried unsuccessfully to manipulate the following to find the answer:
t=5u-1 and u**2=t-5 
Substitute 1st into 2nd to get:
u^2=5u-1-5
u^2-5u+6 = 0
(u-3)(u-2) = 0
u=3 or u=2
----------------
If u = 3 , t=5*3-1 = 14
-------------------------
If u=2, t = 5*2-1 = 9
--------------------------
The ten's digit cannot be 14 so the only solution is 92
=========================================
Cheers,
Stan H.