Answer
1
Work Step by Step
−2.1−[2.3−(3.5−(−1.9))]⟶ in the innermost parentheses, change subtraction to addition, and reverse the sign of the following term
=−2.1−[2.3−(3.5+1.9)]⟶ add in innermost parentheses
=−2.1−[2.3−5.4]⟶ subtract within brackets
=−2.1−[−3.1]⟶ change subtraction to addition, and reverse the sign of the following term
=−2.1+3.1⟶ add
=1
