You multiply 0.6 by 5x and 10 and you get 3x+6=-24. you then subtract 6 from both sides of the equation and you get 3x=-30. after that you divide both sides by 3 and you get x=-10. so the answer is B!
        
             
        
        
        
36.
 Convert 10% to .1, (10 divided by 100)
 then multiply 40 times .1
then subtract 4 by 40
=36
        
             
        
        
        
I am going to assume that you are looking for the speed of the object. So, knowing that the formula for speed is distance divided by time, we have the expression: 45.5/13. This would simplify to be 3.5 meters per second, or m/s. m/s also happens to be the "Scientific unit for speed!" Just a fun fact! If this answer was not clear, please feel free to ask! Happy home-working!
        
             
        
        
        
Multiply the top one by 3 for x, so you can eliminate x and find y
then plug in the y into one of the equations to find x
        
             
        
        
        
Hey there! :D
Make an algebraic expression. 
Let the 'number' equal x. 
4x-24= 60
Add 24 on both sides. 
4x= 84
Divide both sides by 4. 
x=21
The number is 21. 
I hope this helps!
~kaikers