D is the right one, in all these suggestions , the number cube is rolled 1 time. 
        
             
        
        
        
Answer:
-34 -7a
Step-by-step explanation:
–34–23a+16a
Combine like terms
-34 -7a
 
        
                    
             
        
        
        
Answer:
u=2
Step-by-step explanation:
8u-21 = 2u-9
+21             +21
8u= 2u + 12
-2u    -2u
6u= 12
divide by 6, u=2 !!
 
        
                    
             
        
        
        
87/1000 into a decimal is 0.087,
You can divide with your calculator, or you can use place value.
0.8 = 8/10
0.87 = 87/100
0.087 = 87/1000
And so on and so forth...