Question

How do you simplify `2 - 5(3t - 4)`?

Answer 1

`22-15t`

Explanation:

the 5 multiplies everything inside the brackets so you have:

`2 - ( 5 times 3t - 5 times 4)`

`2 - ( 15t -20)`

But that is not the end of it! You have a minus in front of the bracket.
This is the same as multiplying everything inside the brackets by (-1).

By the way, another way of looking at ' plus ' is as 'put with'; and at subtract as 'remove from':

Now we have :

`2 -1(15t-20)`

Just think about the `-1(15t-20)` on its own for now

We have:

`(-1 times 15t) - (-1 times 20)`

`(-15t)-(-20)`

Negative times negative give you a positive so we have
`-15t + 20`

so `2 - ( 15t -20)` becomes `color(white)(xx)2-15t+20`

regrouping gives

`-15t +2+20`

`-15t+22` which is the same as `22-15t`