Answer:
The simplified answer would be 7m+63. You would have to solve for the variable. 
Step-by-step explanation:
 
        
                    
             
        
        
        
<span>speed = distance/time
total time is 8 hours
outgoing speed is 160 km per hour, 
so time = d/160
</span><span>returning speed is 240 km per hour,
so time = d/240
 d/160 + d/240 = 8
3d/480 + 2d/480 = 8
5d/480 = 8
5d =480 (8)
5d = 3840
d=3840/5
d=768
answer: so the distance is 768 km</span>
        
                    
             
        
        
        
The first one is true
<span>4(4a+10)  is 
</span>16 a + 40 after distribution
The second one is also true
<span>2(8a+20) 
16a + 40 after distribution
Third is not true
</span><span>4a(4+10a) 
</span><span>16a + 40a^2 after distribution
Last one is also true
</span><span>8(2a+5)
16a + 40 after distribution
Hope this helps :)</span>