Answer:
Step-by-step explanation:
2nd one
 
        
             
        
        
        
If you are asking 7/8 - 1/x= 3/4,
first put 3/4 to 6/8 to make it easier.
Move the 7/8 over to the right. You will get 1/x=-1/8.
Simplify, it is x=-8.
Check=7/8 - 1/8=6/8
It checks out.
 
        
                    
             
        
        
        
Answer:
Equal to 440
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
Yes, the previous answer was right, 209.40625
Step-by-step explanation:
 
        
             
        
        
        
Answer:
√45
Step-by-step explanation:
We know that according to the Pythagorean theory:
a²+b²=c²
I am pretty sure that a is 3 and b is 6. C remains unknown. 
3 squared is nine and 6 squared is thirty six. 36+9 is 45.
Since the question says you should leave the answer in radical form, the answer is 
c²=45
√c²=√45
This book will really help in Geometry and you can get it anywhere. 
I hope this helps!
~°LampteyJ