The answer for this one is F. I'm 100% sure it's F because T is wrong, the answer can't be all positive numbers. S is wrong because if you distribute the negative sign from -(2.1-5.9), you will get -2.1+5.9, which is not the same as the original expression. U is also wrong because the first one, or the binomial (2.1+5.9), suppose to be negative, not positive. F is the correct answer.
