Question

what is the error ? Sarah evaluated the expression 7-(-5) and came up with answer -12 what did Sarah do wrong ?

Answer 1

it is not 7-(-5) whether it is -7-5.

Answer 2

When we will evaluate the expression 7-(-5)

the negative sign outside the bracket will turn positive after opening of bracket because there is a negative sign inside of the bracket. Hence answer should be

7-(-5) = 7+5 = 12

But her answer is -12, which is wrong due to the negative sign it carries.