Sponsor Area

Remainder and Factor Theorems

Question
ICSEENIMA10018836

Using remainder theorem, find the value of k if on dividing 2 x3 + 3 x2 - k x + 5    by    x - 2, leaves a remainder 7.

Solution

Let   f ( x ) =  2 x3 + 3 x2 - k x + 5

Using remainder theorem,

F ( 2 ) = 7

  2 ( 2 )3 + 3 ( 2 )2 - k ( 2 ) + 5  = 7  2 ( 8 ) + 3 ( 4 ) - k ( 2 ) + 5  = 7 16 + 12 - 2 k + 5 = 7 2 k = 16 + 12 + 5 - 7 2 k = 26 k = 13