Question

Consider this polynomial, where a is an unknown real number.

Answer 1

Answer:

Step-by-step explanation:

Correct steps to find the value of 'a' should be,

Braulio's synthetic division should be,

-1  |     1       5         a          -3           11

   

               -1        -4        (4 - a)     (a - 1)  

         1      4     (a - 4)     (1 - a)     (a + 10)

Here remainder is (a + 10).

So (a + 10) = 17 ⇒ a = 7

Braulio Incorrectly found a value of 'a' because he should have used (-1) instead of 1.

Zahra's calculation by remainder theorem should be,

p(x) = x⁴ + 5x³ + ax² - 3x + 11

p(-1) = (-1)⁴ + 5(-1)³ + a(-1)² - 3(-1) + 11

      = 1 - 5 + a + 3 + 11

      = (a + 10)

Since, remainder of the solution is 17,

(a + 10) = 17 ⇒ a = 7

Zahra incorrectly found the value of 'a' because she incorrectly solved the powers to (-1).