Question

Evaluate 2x^2-1 when x=3

Answer 1

$\sf{\qquad\qquad\huge\underline{{\sf Answer}}}$

Let's evaluate ~

$\qquad \sf \dashrightarrow \: 2 {x}^{2} - 1$

plug in the value of x :

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

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

$\qquad \sf \dashrightarrow \: 18 - 1$

$\qquad \sf \dashrightarrow \: 17$

The required value is 17

Answer 2

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Answer:  $\textsf{Option B, 17}$

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Given:  $\textsf{2x}^2\textsf{ - 1}$

Find: $\textsf{When x = 3}$

Solution: In order to find the value when x is equal to 3 we just need to equate any x to the value of 3 and simplify.

Plug in the values

• $\textsf{2x}^2\textsf{ - 1}$

• $\textsf{2(3)}^2\textsf{ - 1}$

Simplify the expression

• $\textsf{2(3 * 3) - 1}$

• $\textsf{2(9) - 1}$

• $\textsf{18 - 1}$

• $\textsf{17}$

Therefore, the answer that would make most sense would be option B, 17.