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Workbook

Example 3: If x   4 and y = 1, then evaluate the expression

x  y (x 4)   x  y (x 1)   y 1 .

Example 4: If x 0 y  , simplify x y   y .
x

Example 5: If x y 0  , simplify the expression x  x y  x  y .

Example 6: If x y 0  , simplify the expression x  x y  x  y .

3 x y 
Example 7: If x 0 y  , simplify the expression .
y  x

Example 8: What is the sum of the values of x,y andz for the equation 2x 3 3y 1 z 2 0      ?

Example 9: If 2 x 8  and f(x) x 2   x 4  2x 6 , then what is the sum of the least and the

greatest possible values of f(x) ?

Example 10: If a b 0 c   , then simplify the expression ac bc  ac ab  cb ab .

20 091math-wb-w6-(equations&inequalities-1)