Category: Mathematics MCQs

Mathematics Multiple Choice Questions (MCQs) Test with Answers.

What is the value of x2+14x+24, when x=854?

What is the value of x2+14x+24, when x=854?

(A) 10,000
(B) 100,000
(C) 741,296
(D) 742,398

Answer: (C) 741,296

Solution:

To avoid the consuming calculation, factorize the given polynomial
x2 + 14x + 24 = x2 + 12x + 2x + 24 = x(x + 12) +2(x + 12)

=> (x + 2) (x + 12)

Subtracting the value of x in above

=> (854 + 2) ( 854 + 12) = (856) (866)

=> 741,296

The average of the polynomials, 2×2 + 5x -6, 5×2 – 5x – 6 and 30 – 7×2 is:

The average of the polynomials, 2x2 + 5x -6, 5x2 – 5x – 6 and 30 – 7x2 is:

(A) 14
(B) 6
(C) 18
(D) 5x

Answer: (B) 6

Solution:

First, we find the sum of the three polynomials, than divide the answer by 3.
Sum of the three polynomials

2x2 + 5x – 6
5x2 – 5x – 6
-7x2 + 30 / 18

Now, Average = Sum of the three polynomials / 3

= 18 / 3 = 6

so. the answer is 6.

{\displaystyle {\sqrt {~^{~}}}}