Question

Lisa evaluated the expressions 2x and x^2 for x=2 and found that both epressions were equal to 4. lisa concluded that 2x and x^2 are equivalent expressions. How could you show lisa that she is incorrect?

190 points

Answer 1

because X squared isn't the same as 2 multiplied by X(any variable) meaning the moment you change your variable the expressions wouldn't equivalent.

EX.) 2*420=840 and 420^2=176400

Answer 2

Choose another number.

Explanation

We could take x=3 and evaluate, for the first expression we would have

`2x=2\cdot3=6`

and for the secod expression we would have

`x^2=3^2=9`

For this choosen x, we would have

`2x=6\\eq9=x^2`

which would show lisa that she is incorrect.