Question

When Sam simplified the expression 3.5 - (-4.1), she got -0.6.

What mistake did Sam likely make when she simplified
the expression?

Answer 1

She subtracted a negative incorrectly by simply subtracting a positive when subtracting a negative means to add a positive.

Explanation:

She subtracted 3.5 - 4.1 which is -0.6

The problem is subtracting -4.1 which means to add 4.1

3.5 - (-4.1) = 3.5 + 4.1 = 7.6

She did: 3.5 - (-4.1) = 3.5 - 4.1 = -0.6 which is incorrect.

Answer 2

She forgot to combine the 2 negative signs and turn it into a positive.

Explanation:

When you subtract a negative, you are adding the number. So if we have 3.5 - (-4.1), it would equal 3.5 + 4.1, which is 7.6