Question

Question #ec859

Answer 1

`18`

Explanation:

`48/2+4^2-(6+2)xx3`

`=48/2+16-(6+2)xx3`

`=48/2+16-(8xx3)`

`=48/2+16-24`

`=48/2-8`

`=24-8`

`=16`

Answer 2

`16`

Explanation:

In any calculation involving multiple operations, you have to know the correct order in which to do them. This is usually known as PEDMAS, BODMAS or similar.

I prefer to work with the concept of TERMS. Terms are separated by single PLUS or MINUS signs.

Each term is simplified separately to give a single answer and these are added or subtracted in the last step.

Within each term, the order is brackets, then indices, and then multiplication and division.

`" "color(red)(48/2)color(lime)(+4^2)color(blue)( -(6+2)xx3)" "` has 3 terms. Work out each:
`color(white)(....)darrcolor(white)(...)darrcolor(white)(......)darr`
`=color(red)(24)color(lime)(+16)" "color(blue)( -(8xx3)`
`color(white)(....)darrcolor(white)(...)darrcolor(white)(.........)darr`
`=color(red)(24)color(lime)(+16)" "color(blue)( -24`

It is a good idea to write the ADD terms at the front and the SUBTRACT terms at the end.

This expression is already in this order.

`=24+16-24" "larr` work from left to right

`=40-24`

`=16`

You could also have noticed that:

in `color(red)(24)color(lime)(+16)color(blue)( -24)` there are additive inverses.

`color(red)(+24)color(blue)( -24) = 0`

Therefore `=color(red)(cancel24)color(lime)(+16)color(blue)( cancel(-24)) = 16`