Question

plz slove ques. no. 31 plz....

Answer 1

Given f(x) = x^3 - 10x^2 + ax + b

Given that (x - 1) is a factor of f(x).Therefore f(1) = 0

= > f(1) = (1)^3 - 10(1)^2 + a(1) + b = 0

= > 1 - 10 + a + b = 0

= > a + b = 9  ------ (1)


Given that (x - 2) is a factor of f(x), we get f(2) = 0

= > f(2) = (2)^3 - 10(2)^2 + a(2) + b = 0

= > 8 - 40 + 2a + b = 0

= > 2a + b = 32  ------ (2)


On solving (1) & (2),we get 

2a + b  = 32

a + b = 9

--------------------

   a = 23.


Substitute a = 23 in (1), we get

= > a + b = 9

= > 23 + b = 9

= > b = -14.


Therefore the value of a = 23, b = -14.


Hope this helps!

Answer 2

i hope it will be helpful.......