# values of a and b

• September 9th 2012, 01:45 AM
rcs
values of a and b
if the quotient obtained in dividing x^2 - 7x + b by x + a is x - 2, and the remainder is 5, then what are the values of a and b?

anybody can help on this?

thanks
• September 9th 2012, 02:14 AM
kalyanram
Re: values of a and b
We have $(x - 2)(x + a)+5 = x^2 - 7x + b$. Expanding the LHS and comparing the coefficients on both sides we have $a=-5, b= 15$
• September 9th 2012, 02:21 AM
MarkFL
Re: values of a and b
We are told:

$x^2-7x+b=(x-2)(x+a)+5=x^2+(a-2)x+(5-2a)$

Now, equate coefficients to get two equations, from which you may determine a and b.