a – b + -1(a + b)

a + -b + -a + -b

a + -a + -b + -b

-b + -b

-2b

2. -x

-7

3. -(3x + 5y)

-3x + -5y

-3x – 5y

4. [7 (8 – 2) +9] – [13 – 2 (7 – 4) – 8]

In this problem use the following: Please Excuse My Dear Aunt Sally

That means: Parenthesis, Exponents, Multiplication and Division, Addition and Subtraction

So start with the parenthesis

[7 (6) + 9] – [13 – 2(3) – 8]

The 7(6) and 2(3) is multiplication

[42 + 9] – [13 – 6 – 8]

The […] are the same as parenthesis

(42 + 9) – (13 – 6 – 8)

(51) – (7 – 8)

(51) – (-1)

51 – -1

51 + 1

52

5. You typed this problem wrong because 4 – (7) -3 is 4-(7 x -3) is 4 – -21 is 25 and 25 does not equal 0.

a-b-(a+b)

If you go to the section in your text that goes over properties, you will find that you can distribute the “-” to (a+b). So, after we distribute the negative sign, we get a-b+(-a-b) which then can be read as a-b-a-b.

For finding X when X is 7, I am assuming that they want you to plug in the 7 and solve the equation. If the problem really just says exactly what you have typed than -X is -7. I would have to see your textbook.

Additive inverse will also be found in the properties section. The additive inverse’s sum is 0. If we have -(3x+5y) then we need the appropriate number/variables that will cancel -(3x+5y). Please also refer to my first comment about a-b-(a+b) if you are having trouble seeing how adding (3x+5y) would cancel out -(3x+5y).

In the shown problem where you ask if it is correct:

Use the Please Excuse My Dear Aunt Sally approach system of solving equations. 1) Deal with what is in the Parantheses (). 2)Deal with the Exponents 3) the multiplication 4) division 5) addition 6) Subtraction

You made a mistake in the -[13-2(7-4)-8]. Go back and check again.

The simplify part does not work. -6 does not equal 0. Just put a slash through the equals sign.

Hope this has helped. Email me if you have any other questions. Good luck.

a – b – (a + b)

= a – b – a – b

= -b -b

= -2b

a) -x when x is 7 = -7

b) -3x -5y

c) =[7(6) + 9] – [13 – 2(3) – 8]

=[42 + 9] – [13 – 6 – 8]

= [51] – [7 – 8]

= [51] – [-1]

= 51+1 = 52

d) -3 – 3= 0

-6 = 0