Question #dfc9b

1 Answer
Nov 2, 2016

Answer:

This isn't the place to get answers for your homework, so I won't give them to you. But I will help you understand how to answer these questions yourself.

Explanation:

The only concept that needs addressing in this answer is how to expand brackets.

With addition, brackets can be removed with not problem. So, #a + (b+c) = a+b+c# and #a+(b-c)=a+b-c#.

With subtraction, we have to be a bit more careful. When expanding a bracket with a minus sign before it, we have to remember the sign of each term changes (because we multiply it by #-1#). So, #a-(b+c) = a-b-c# and #a-(b-c) = a-b+c#.

The final thing to mention is that when bringing like terms together, we use the sign that comes before the terms and not the operation. So, #(2a+1) - (a-5) = 2a+1-a+5 = a+6# and #(2a+1) + (5-a) = a+6#. Although the operation in the second example was addition, we subtract as the sign before #a# was #-#. This is an area where students can easily make mistakes..