Advertisements
Advertisements
Question
Prove by factor theorem that
(x - 3) is a factor of 5x2 - 21 x +18
Solution
x - 3 = 0 ⇒ x = 3
Substituting this value , we get
f(3) = 5(3)2 - 21(3) + 18
= 45 - 63 + 18
= 0
APPEARS IN
RELATED QUESTIONS
Find the value of ‘k’ if (x – 2) is a factor of x3 + 2x2 – kx + 10. Hence determine whether (x + 5) is also a factor.
Prove by factor theorem that
(2x+1) is a factor of 4x3 + 12x2 + 7x +1
Find the value of m ·when x3 + 3x2 -m x +4 is exactly divisible by (x-2)
By factor theorem, show that (x + 3) and (2x – 1) are factors of 2x2 + 5x – 3.
Show that (x – 2) is a factor of 3x2 – x – 10 Hence factorise 3x2 – x – 10.
Use factor theorem to factorise the following polynominals completely.
x3 + 2x2 – 5x – 6
Find the value of the constants a and b, if (x – 2) and (x + 3) are both factors of the expression x3 + ax2 + bx – 12.
If (x + 2) and (x – 3) are factors of x3 + ax + b, find the values of a and b. With these values of a and b, factorise the given expression.
Determine whether (x – 1) is a factor of the following polynomials:
x4 + 5x2 – 5x + 1
Find the value of 'a' if x – a is a factor of the polynomial 3x3 + x2 – ax – 81.
