Before you study what is multiplication of variables, you are advised to read:
 
  What are Variables ? 
 
  You will also face following situation under this concept: 
 
  Multiplication of Two or more Positive Variables
  Multiplication of Two Negative Variables
  Multiplication of Three or more Negative Variables
  Multiplication of Positive and Negative Variables
 
  Multiplication of Two or More Positive Variables 
 
  Example 1: Multiple x and y 
 Solution: In the given question:
 x and y are both variables
 
 Multiplication expression gives us:
 x X y
 
 On solving the multiplication expression, we get:
 xy
 
 Hence, multiplication of (x) and (y) give us (xy)
 
  
  Example 2: Multiple b and a 
 Solution: In the given question:
 b and a are both variables
 
 Multiplication expression gives us:
 b X a
 
 On solving the multiplication expression, we get:
 ba
 
 or we write it as
 ab   (because variable are arranged in alphabetical order)
 
 Hence, multiplication of (b) and (a) give us (ab)
 
  
  Example 3: Multiple  z, y and x 
 Solution: In the given question:
 z, y and x are variables
 
 Multiplication expression gives us:
 z X y X x
 
 On solving the multiplication expression, we get:
 zyx
 
 or we write it as
 xyz  (because variable are arranged in alphabetical order)
 
 Hence, multiplication of (z), (y) and (x) give us (xyz)
 
 
  Multiplication of Two Negative Variables: 
 (This is similar to  Multiplication of Two Negative Integers)
 
 
  Example 4: Multiply (-M) and (-N) 
 Solution: In the given question:
 (-M) and (-N) are negative variables
 Multiplication expression gives us:
 (-M) X (-N)
 
 Now, we have two negative variable  i.e. (-M) and (-N)
 So we will multiply (M) and (N) (as explained in example 1, 2 and 3) and put positive sign or addition operator to the left of product & we get:
 +MN                         
 
 Or we can write it as:
 MN
 
 Hence, Multiplication of (-N) and (-M) give us (MN)
 
  Multiplication of Three or more Negative Variables 
 (This is similar to  Multiplication of Three or more Negative Integers )
 
 
  Example 5: Multiply (-p), (-q) and (-r) 
 Solution: In the given question:
 (-p), (-q) and (-r) are negative variables
 Multiplication expression gives us:
 (-p) X (-q) X (-r)
 
 Now, we have three negative variables i.e. (-p), (-q) and (-r)
 So we will multiply these variables (as explained in example 1, 2 and 3) and ignore negative sign or subtraction operator & we get:
 pqr                         
 
 Now we put negative sign or subtraction operator i.e. (-) to the left of (pqr) & we get:
 (-pqr)
 
 Hence, Multiplication of (-p), (-q) and (-r) give us (-pqr)
 
  Example 6: Multiply (-	a), (-b), (-c) and (-d) 
 Solution: In the given question:
 (-a), (-b), (-c) and (-d) are negative variables
 Multiplication expression gives us:
 (-a) X (-b) X (-c) X (-d)
 
 Now, we have four negative variables i.e. (-	a), (-b), (-c) and (-d)
 So we will multiply these variables (as explained in example 1, 2 and 3) and put positive sign or addition operator to the left of product & we get:
 +abcd               
 
 Or we can write it as:
 abcd
 
 Hence, Multiplication of (-	a), (-b), (-c) and (-d) give us (abcd)
 
 
  Multiplication of Positive and Negative Variables 
 (This is similar to  Multiplication of Positive and Negative Integer) 
 
  Example 7: Multiply (x) and (-y) 
 Solution: In the given question:
 x is a positive variable
 (-y) is a negative variable
 
 Multiplication expression gives us:
 x X (-y)
 
 Now, we have one positive variable i.e. (x) and one negative variable i.e. (-y)
 So we will multiply these variables (as explained in example 1, 2 and 3) and ignore negative sign or subtraction operator i.e. (-) & we get:
 xy                         
 
 Now we put negative sign or subtraction operator i.e. (-) to the left of (xy) & we get:
 (-xy)
 
 Hence, Multiplication of (x) and (-y) give us (-xy)
 
        
        
        
        
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