asked 20.4k views
0 votes
8) Find the values of m and n in the polynomial 2x³ + mx² + nx - 14 such that (x-1) and (x + 2) are factors. ​

1 Answer

7 votes

Answer:

m = 9 and n = 3

Explanation:

To find the values of m and n in the polynomial 2x³ + mx² + nx - 14 such that (x - 1) and (x + 2) are factors, we can use the factor theorem.

According to the factor theorem, if (x - r) is a factor of a polynomial, then the polynomial will be equal to 0 when we substitute x = r.

Using this theorem, we can find the values of m and n by substituting x = 1 and x = -2 into the given polynomial and setting them equal to zero.

For (x - 1) = 0,

we have:

2(1)³ + m(1)² + n(1) - 14 = 0
2 + m + n - 14 = 0
m + n = 12 -- (Equation 1)

For (x + 2) = 0,

we have:

2(-2)³ + m(-2)² + n(-2) - 14 = 0
-16 + 4m - 2n - 14 = 0
4m - 2n = 30 -- (Equation 2)

Now we have a system of equations (Equation 1 and Equation 2) to solve simultaneously.

From Equation 1, we can express m in terms of n:

m = 12 - n

Substituting this into Equation 2:
4(12 - n) - 2n = 30
48 - 4n - 2n = 30
48 - 6n = 30
-6n = 30 - 48
-6n = -18
n = -18 / -6
n = 3

Substituting n = 3 into Equation 1:
m + 3 = 12
m = 12 - 3
m = 9

Therefore, the values of m and n that satisfy the given conditions are m = 9 and n = 3.
answered
User Pepoluan
by
7.4k points

Related questions

asked Apr 5, 2022 31.7k views
Woof asked Apr 5, 2022
by Woof
8.5k points
1 answer
2 votes
31.7k views
Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.