INEQUALITIES 8

If │2x – 7 │= 21; Find  x

Solution

±(2x – 7 )= 21

2x -7= 21    OR   –(2x-7) = 21

2x – 7 = 21    OR   -2x+7= 21

2x = 21 + 7    OR   -2x= 21-7

2x = 28     OR   -2x  =  14

2      2                2        2

x = 14  OR  x = 7

Hence x = 14 OR x = 7     

TRY THIS...............................

If │4x – 16 │= 32; Find  x