Question

Evaluate 2x^2-1 when x=3

Answer 1

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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.

Answer 2

`\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