what is the difference of (-4ab-5a+3)-(-7ab+9)

Question

I don't understand Algebra 1. 

Answer 1

Here's HOW to conquer this particular challenge, or other like it.

 

You DISTRIBUTE the minus sign that is outside the expression within the second set of parentheses. This changes all their signs.  Since there is nothing to distribute outside the FIRST parenthesized set of parentheses, just discard those.

 

Then you have: 

-4ab -5a +3 +7ab - 9

Next, you COLLECT 'LIKE' terms; the result is 3ab - 5a - 6.

 

Spend enough time learning from your book, from your teacher's explanations, and from you homework to REALLKY LEARN. OTHERWISE your entire time in school will be tortuous--you simply MUST ake your studies seriously.

Answer 2

  Write the expressions like a very simple subtraction problem:

 

   -4ab   -   5a    +   3

 - (-7ab               +9)

---------------------------   [remember, it is subtraction]

     3ab  -   5a     -  6

 

Now, learn to do it as algebra, by distributing the "-," than by collecting like terms.