Question

Evaluate: −[4.2−3(2.1)]−0.2+1

What is the value of the expression? Enter your answer as a decimal in the box.

Answer 1

To evaluate −[4.2−3(2.1)]−0.2+1, apply the order of operations to get the result, which is 2.9. This includes multiplication inside the brackets, subtraction inside the brackets, changing signs as the brackets are removed, then tackling the addition and subtraction outside the brackets in sequence.

The value of the expression is 2.9.

Step-by-step explanation:

The student asked to evaluate the expression −[4.2−3(2.1)]−0.2+1. To solve this, follow the order of operations, which is Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right), often remembered by the acronym PEMDAS.

• Inside the parentheses: calculate 3 times 2.1, which gives 6.3.
• Now subtract 6.3 from 4.2: −(4.2 − 6.3) = −(−2.1).
• Remove the parentheses and change the signs: −(−2.1) becomes +2.1.
• Add the numbers outside the parentheses: +2.1 − 0.2 + 1.
• Now combine these: 2.1 − 0.2 = 1.9; finally, add the 1 to get 2.9.