You find the LCM of the denominators in the fractions, then you multiply both fractions as needed till both have like denominators. Then you subtract.
For example:
5/9 - 2/4
LCM of 9 and 4 is 36
[(5 x 4)/(9 x 4)] - [(2 x 9) - (4 x 9)]
= 20/36 - 18/36
20/36 - 18/36 = 2/36
2/36 = 1/18
hope this helps ya!
        
             
        
        
        
Answer:
Step-by-step explanation:
x + 12 = y
x = y - 12
 
        
             
        
        
        
Answer: x=4
Step-by-step explanation:
5x=15+5
15+5=20
5x=20
divide 5 on both sides 
20/5=4
x=4
 
        
                    
             
        
        
        
Answer:
48
Step-by-step explanation:
A square has 4 sides of equal length. 12 x 4=48