Answer:
-0.4 should be in between 0 and -0.5, however be as close to -0.5 as possible while not being ON -0.5.
3 4/5 should be in between 3 and 4, so you can split 4/5 into 8/10 which are equal to each other. Then you can pretend to split the 3 and 4 gap into 10 equal pieces. After you split the gap, count 8 parts to the left of 3.
Step-by-step explanation:
I hope you understand what I mean.
 
        
             
        
        
        
Answer

Step-by-step explanation:
 

 
        
             
        
        
        
Answer:
20:15
Step-by-step explanation:
baiscally add 4:3 
4+3=7 
then take the total of 35 and divide it by 7 you'd get 5.
4x+3x=35 
7x=35
1x=5
4x=5×4=20
3x=5×3=15 
4:3 therefore would be 20:15
 
        
             
        
        
        
Answer: b = 69
The slashes mean the opposite angles are the same. This is and isosceles triangle, which mean two sides are the same and one is not. 
A triangle = 180
We know one angle is 42 and the other two angles are the same.
Subtract 42 from 180
180 - 42 = 138
Now the 138 is going to two sides but we know they are equal so we can divide 138 by 2
138 divided by 2 = 69
So b = 69