Let's solve your equation step-by-step. 
25m+100−24m−75=68 
Step 1: Simplify both sides of the equation. 
25m+100−24m−75=68 
25m+100+−24m+−75=68 
(25m+−24m)+(100+−75)=68(Combine Like Terms) 
m+25=68 
m+25=68 
Step 2: Subtract 25 from both sides. 
m+25−25=68−25 
m=43 
Answer: 
m=43