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Calculate |2 - 3^2| + (-1)^3

Step by step, with the reason for every step · Powers, square roots, absolute value · Foundations

Step by step

The question

Question: work out |2 − 3²| + (−1)³.

|2 − 32| + (−1)3

1 Inside the bars

The bars work like brackets.

They come first.

Powers come before minus.

Order: ( ) → x² √ → × ÷ → + −

3² means 3 times 3.

32 = 3 × 3 = 9

That is 9.

= |2 − 9| + (−1)3

We take away more than we have.

Start at 2.

Go down 9.

We pass 0 and land on −7.

= |−7| + (−1)3

2 Absolute value

| | = how far from 0

The bars mean: how far from 0?

That is never negative.

So |−7| is 7.

= 7 + (−1)3

3 Powers

Powers come before plus.

(−1)³ means −1 times −1 times −1.

An odd number of minuses gives minus.

(−1)3 = (−1) × (−1) × (−1) = −1

That is −1.

= 7 + (−1)

4 Plus and minus

Adding a negative is the same as taking away.

+ (−) = −

So 7 + (−1) becomes 7 − 1.

= 7 − 1

7 minus 1 is 6.

= 6

So the answer is 6.

Let's look back.

First: inside the bars.

Then: absolute value.

Then: powers.

Last: plus and minus.

Answer
= 6

Your turn

Try this one yourself, then check:

Work out |3 − 42| + (−1)3
Show the answer
12

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