Question

How do you simplify `-3(4x-1)+9x+8x`?

Answer 1

Just in case it is needed; I have explained about multiplying the bracket.

Explanation:

Further explanation about how to handle `-3(4x-1)`

Consider as an example `2xxa -> 2a`

This means we have two of `a`

That is `a+a`

So `3a` means we have three of `a`. That is `a+a+a`

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ok! carry that thought into`" " -3(4x-1)`

for a moment forget that this is multiplied by negative 3. Just think it as being multiplied by positive 3

So`" "3(4x-1)" is the same as " 3xx(4x-1)`

Which is the same as`" " (4x-1)+(4x-1)+(4x-1)`

Which is the same as`" " 4x-1+4x-1+4x-1`

Which is the same as`" " 4x+4x+4x-1-1-1`

Which is the same as `color(green)(" "12x-3)`

Notice that you have ended up with the same expression as you would do if you multiplied every thing inside the bracket with 3

Now all you have to do is deal with the negative bit.

`-1xx(12x-3) = (-1xx12x)+(-1xx-3)`

`(-12x)+(+3) = -12x+3`

`color(blue)("I hope this helps!")`