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

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Answer 1 · 2016-02-28T19:35:53

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

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!")#