Answer:
14411
Step-by-step explanation:
 
        
             
        
        
        
1 hour = 60 minutes 
1 hour:45 minutes 
= 60 minutes:45 minutes
=12 minutes:9 minutes
        
                    
             
        
        
        
Answer:
4: 3
Step-by-step explanation:
In this case, we have that there is a relationship between width and height, which is 16: 9, which means that any screen that has the same ratio would be an identical screen.
How would we do this? it must either be raised to a power or rationalized on both sides of the ratio.
If we raise to a power, it would give very large dimensions for an HDTV, therefore, it is best to remove the square root on both sides, since it has more common values for a TV.

4: 3
Therefore, a 4: 3 screen is a good choice for an HDTV with the same ratio.
 
        
             
        
        
        
Answer:
7. x = 3
Step-by-step explanation:
To find the value of x, use the triangle sum property. Every triangle has interior angles which add to 180 degrees. To solve, add the expressions and numbers together then set equal to 180. Then use inverse operations to solve for x.
7. 20x - 9 + 10x + 9 + 90 = 180             Subtract 90 from both sides.
    20x - 9 + 10x + 9 = 90                       Add -9 + 9 = 0
    20x + 10x = 90                                  Add like terms 20x + 10x = 30x
    30x = 90                                            Divide both sides by 30.
         x = 3
Repeat this process for each problem.