Question

rind the value of the polynomial 3x² 4x² +7x-5, when
x=3 and also when x=-3.
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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.