Question

. Find the value of the polynomial 3x3 – 4x2 + 7x – 5 , when x = 3 and x = -3

Answer 1

$\bf{\underline{\underline{Question}}}$

$\:$

$\small\tt{Find\:the\:value\:of\:the\: polynomial}$$\small\tt{f(x)\:=\:3x^{3}-4x^{2}+7x-5}$

$\small\tt{When\:x\:=\:(3)\:and\:(-3)}$

$\:$

$\bf{\underline{\underline{Solution}}}$

$\:$

$\small\tt{f(x)\:=\:3x^{3}-4x^{2}+7x-5}$

$\:$

$\small\bf{Case\:(i)}$

$\:$

$\small\tt{f(3)\:=\:3(3)^{3}-4(3)^{2}+7(3)-5}$

$\:$

$\small\tt{f(3)\:=\:81-36+21-5}$

$\:$

$\small\tt{f(3)\:=\:61}$

$\:$

$\small\bf{Case\:(ii)}$

$\:$

$\small\tt{f(-3)\:=\:3(-3)^{3}-4(-3)^{2}+7(-3)-5}$

$\:$

$\small\tt{f(-3)\:=\: -81-36-21-5}$

$\:$

$\small\tt{f(-3)\:=\: -143}$

$\:$

$\bf{\underline{\underline{Thanks}}}$

Answer 2

Answer:

$3 {(x)}^{3} - 4 {(x)}^{2} + 7x - 5 \\ 3{(3)}^{3} - 4 {(3)}^{2} + 7(3) - 5 \\ 3(27) - 4(9) + 21 - 5 \\ 81 - 36 + 21 - 5 \\ 45 + 21 - 5 \\ 66 - 5 \\ \\ = 61$

$3{(x)}^{3} - 4 {(x)}^{2} + 7(x) - 5 \\ 3 {( - 3)}^{3} - 4 {( - 3)}^{2} + 7( - 3) - 5 \\ 3( - 27) - 4(9) - 21 - 5 \\ - 81 - 36 - 21 - 5 \\ - 117 - 21 - 5 \\ - 138 - 5 \\ \\ = - 143$

Step-by-step explanation:

HOPE IT WILL HELP YOU

PLZZ MARK AS BRAINLIST