what is 4(3x + -2) + 6x(2 + -1)

Question

i need help

Answer 1

Martin G. did well.  I will just add to his answer as follows.

 

First of all, books show students some poor ways of writing practiced by many, but don't take those as an example of how it should be done.

 

2 + -1  should be written as 2 + (-1) or  2 + [-1]).  This will help alert the reader, drawing attention to the negative sign.

 

4(3x + [-2]) + 6x(2 + [-1])   =  

4(3x + [-2]) + 6x(   1       )   =

4(3x + (-2)) + 6x

 

 

Four times (3x - 2) is the same as adding [3x + (-2)] four times.

 

   3x + (-2)

+ 3x + (-2)

+ 3x + (-2)

+ 3x + (-2)

+ 6x

  _________

 

  18x + (-8)    =     18x - 8.

 

Finally it is obvious the parenthesis are not needed.

 

 

Answer 2

First simplify the parentheses:

 

4(3x+-2) + 6x(2+-1)=

4(3x-2)+6x(2-1)=

4(3x-2)+6x(1)=

 

now apply the distributive law

 

12x-8 + 6x =

18x-8

 

Hope this helps!