Question

What is the missing number? 2.1 + (–3.4 + 5) = [ + (–3.4)] + 5

Answer 1

2.1 + (–3.4 + 5) = [ + (–3.4)] + 5 = false

2.1 + (–3.4 + 5) = 3.7

[ + (–3.4)] + 5 = 1.4

Thus your answer is 2.1