find the value of the polynomial `3x^(3)-4x^(2)+7x-5,` , when x=3 and also when x=-3.

Explanation

Let p(x) `=3x^(3)-4x^(2) +7x-5`
`p(3) =3(3)^(3)-4(3)^(2)+7(3)-5`
`=3xx27-4xx9+21-5`
`=81-36+21-5`
` therefore " "p(3)=61`
AT `x=-3,p(-3)=3(-3)^(3)-4(-3)^(2)+7(-3)-5`
`=3(-27)-4xx9-21-5`
`=-81-36-21-5=-5=-143`
` p(-3)=- 143`
Hence , the value of the given polynomial at x=3 and x=-3 are 61 and -143 , respectively.