When f(x) = x^3 - 4x^2 + ax + b is divided by (x+3), the remainder is -64. (x-5) is a factor of f(x). Find the values of a and b. HEEELP PLEASE!

Question

anonymous · Answer

$$
\frac {x^3 - 4x^2 + ax + b}{ x+3}=21 + a - 7 x + x^2+ \frac {-63 - 3 a + b}{ x+3}\
-64 = -63 - 3 a + b\
3a -b =1
$$
Try to find another relation between a and b

anonymous · Answer

$$ f(5)=0\ 25 + 5 a + b =0\ 5 a + b = -25 $$

anonymous · Answer

Solve for a and b and you find
a = -3, b = -10

alexwee123 · Answer

wait :o

alexwee123 · Answer

nm ....

anonymous · Answer

Your polynomial is
$$
f(x) = x^3-4 x^2-3 x-10
$$

anonymous · Answer

OHHHH ok I see :D thank you so much! I have trouble with long division polynomials -_-

anonymous · Answer

yw