Question

Find the value of algebraic expression x^3 - 3x^2y +9 if x = -1 , y = 2 ​

Answer 1

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Let's solve ~

$\qquad \sf  \dashrightarrow \: x {}^{3} - 3 {x}^{2} y + 9$

Now, use the given values :

• x = -1

• y = 2

$\qquad \sf  \dashrightarrow \: ( - 1) {}^{3} - (3 \times ( - 1) {}^{2} \times 2) + 9$

$\qquad \sf  \dashrightarrow \: - 1 - ( 3\times 1 \times 2) + 9$

$\qquad \sf  \dashrightarrow \: - 1 - 6 + 9$

$\qquad \sf  \dashrightarrow \: - 7 + 9$

$\qquad \sf  \dashrightarrow \: 2$