Question 97467
You got the equation wrong. 
The qustion says one number is 5 more than the other 

which can be writen as x + 5 (and not 5x which means 5 times the other number)  where x is the first number 

now it's pretty easy to solve 
 x+ x+ 5 =285
 2x = 280
x= 145
and x+5 =145

numbers are 140 and 145