Question

Explain what is wrong with the following argument - be specific.

lim x→2 x^2 +3x-10/x^2-x-2 = (x-2)(x+5)/(x-2)(x+1) = x+5/x+1 = 2+5/2+1 = 7/3

Answer 1

Refer to the attached image.

Answer 2

Explanation:

brackets are missing.

it should look like

lim x→2 (x² + 3x - 10)/(x² - x - 2) =

= (x - 2)(x + 5)/((x - 2)(x + 1)) = (x + 5)/(x + 1) =

= (2 + 5)/(2 + 1) = 7/3

content-wise there is nothing wrong with the argument.

left and right limits are the same.

so, the result is correct.