Alan found the value of the expression (15 - 6)2 to be 189. Is he right?

Question

shadelily · Answer

Everything that is in brackets has to be done first so
15 - 6 = 9
Then do the rest.
9 * 2 = 18 not 189, thus the answer is that Alan is not right.

asc.bchs · Answer

Another way to do this is to distribute the two. 2(15 - 6) = 30 - 12 = 18. Same answer that @ShadeLily got, but different way to do it. Either way, Alan is wrong.

mathstudent55 · Answer

My guess is that the 2 is an exponent, but of course, I can't be sure.

$\Large (15 - 6)^2$

Correct:

$\Large (15 - 6)^2 = 9^2 = 81$

Incorrect (maybe what Alan did):

$\Large (15 - 6)^2 \color{red}{=} 15^2 - 6^2 = 225 - 36 = 189$

The first equal sign above is in red because it is incorrect. That is the step that Alan did wrong.

mathmale · Answer

In the future, please use the symbol " ^ " to indicate exponentiation.

(15-6)2 is ambiguous.     You want (15-6)^2.

mathmale · Answer

Agreed.  And then 9^2=?