Question

How do you simplify `7(0.2p+0.3q)+5(0.6p-q)`?

Answer 1

`4.4p-2.9q`

Introducing you to a really cool trick.

Explanation:

Do not like decimals so lets get rid of them.

Multiply everything by 1 but in the form of `color(red)(1=10/10)`

If we do the division by 10 at the end we would have the correct answer.

Note: Using an example suppose we had `10(a+b)`. This is the same as `10a+10b`

So using the above principle:

`color(green)(color(red)(10/10)[color(white)(2/2)7(0.2p+0.3q)+5(0.6p-q)color(white)(2/2)]`

`color(green)(color(red)(1/10)[color(white)(2/2)color(white)("b")7(2p+3q)color(white)("bb")+5(6p-10q)color(white)(2/2)]`

`color(green)(color(red)(1/10)[color(white)(2/2)14p+21q+30p-50qcolor(white)(2/2)]`

`color(green)(color(red)(1/10)[color(white)(2/2)44p-29qcolor(white)(2/2)]`

`color(white)("bbbbb")color(green)(4.4p-2.9q)`