Question

Evaluate `[2(42-9)+3]-1?`

Answer 1

`68`

Explanation:

Using order of operations, we can solve this problem. You can remember this order by the acronym PEDMAS.
`color(blue)"P"`arentheses
`color(blue)"E"`xponents
`color(blue)"D"`ivision and `color(blue)"M"`ultiplication (left to right)
`color(blue)"A"`ddition and `color(blue)"S"`ubtraction (left to right)

So your equation looks like this. It's special because it actually has brackets and parentheses. That means that you do the inner parentheses first before you ever consider the outer set of brackets.

`[2(42 - 9) + 3] - 1`

I will highlight the numbers that we are working with so that you won't get lost.
`[2(color(green)42 - color(green)9) + 3] - 1`

`[2(color(green)33) + 3] - 1`

Now multiply, since we have no exponents or division:

`[color(brown)2(color(brown)33) + 3] - 1`

`[color(brown)66 + 3] - 1`

Now add the last two integers inside the brackets:

`[color(orange)66 + color(orange)3] - 1`

`[color(orange)69] - 1`

Remove the brackets and subtract:

`69 - 1 rarr 68`

Answer 2

`68`

Explanation:

`"evaluate the expression inside the bracket"`

`[2(33)+3]-1larrcolor(blue)"evaluate parenthesis"`

`=[66+3]-1larrcolor(blue)"multiplication"`

`=[69]-1larrcolor(blue)"addition"`

`=69-1=68larrcolor(blue)"subtraction"`

Answer 3

`68`

Explanation:

To solve this problem you need to follow the rules of BODMAS. This stands for: Brackets, Orders of powers and (Of) , Division, Multiplication, Addition and Subtraction.

`[2(42-9)+3]-1`

Therefore, the first step is to do the what's in the brackets in order:
(brackets, multiplication then addition)

`(42-9)=33`
`2 xx (33)=66`

(simplify in the brackets)

`[66+3]=[69]`
The last step is to subtract the `1` on the outside of the brackets :

`69-1=68.`

And it's done. Hope this helps.