Question

find the value of the polynomial 3 into power of 3 - 4 into power of 2 + 7 into minus 5 when x is equal to 3​

Answer 1

Answer:

Let p(x) =3x3 – 4x2 + 7x – 5

At x= 3, p(3) = 3(3)3 – 4(3)2 + 7(3) – 5

= 3×27-4×9 + 21-5 = 81-36+21-5 P( 3) =61

At x = -3, p(-3)= 3(-3)3 – 4(-3)2 + 7(-3)- 5

= 3(-27)-4×9-21-5 = -81-36-21-5 = -143 p(-3) = -143

Hence, the value of the given polynomial at x = 3 and x = -3 are 61 and -143, respectively.

Answer 2

Answer:

Answer below

Step-by-step explanation:

Given, the polynomial is 3x³ - 4x² + 7x - 5.

We have to find the value of the polynomial at x = 3 and x = -3.

Let p(x) = 3x³ - 4x² + 7x - 5

p(3) = 3(3)³ - 4(3)² + 7(3) - 5

= 3(27) - 4(9) + 21 - 5

= 81 + 21 - 36 - 5

= 102 - 41

= 61

Therefore, at x = 3 the value of the polynomial is 61.

p(-3) = 3(-3)³ - 4(-3)² + 7(-3) - 5

= 3(-27) - 4(9) - 21 - 5

= -81 - 36 - 26

= -81 - 62

= -143

Therefore, at x = -3 the value of the polynomial is -143.