Question 994546
"Sum of a two-digit number is 13", means the two digit number IS 13.  You would then already know the number and not solve for it.


If the sum OF THE DIGITS of a two-digit number is 13, then this is very different.



t, the tens digit
u, the units or ones digit
Number is 10t+u.
t+u=13.
The "next" part of the description means,  (10t+u)*6=456.


Solve this system:
{{{system(t+u=13,6(10t+u)=456)}}}.