Patricia S. answered • 11/24/14
Tutor
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Math Tutoring for K-12 & College
Hi, Tamaria!
No worries about having trouble with math. A lot of people do! Let's walk through the problem step by step, and don't forget about the order of operations: PEMDAS! (PEMDAS stands for Parenthesis, Exponents, Multiplication/Division - in the order of which comes first as you read from left to right, Addition/Subtraction - in the order of which comes first as you read from left to right)
Directions: Simplify 8 - [x - (5+x)]
Step 1: Parenthesis - There are no like terms inside 5+x, so we can skip this step for now.
Step 2: Exponents - There are no exponents.
Step 3: Multiplication/Division - There are 2 places that we can multiply:
8 - [x - (5+x)] is the same as 8 + -1*[x + -1*(5+x)]
1st - Distribute the -1 through to the x + -1*(5+x) first:
8 + -1*[x + -1*(5+x)] = 8 + [-1*x + -1*-1*(5+x)]
= 8 + [-x + -1*-1 *(5+x)]
2nd - Multiply the two -1s that are in front of the (5+x). Remember,
a negative times a negative is a positive!
8 + [-x + -1*-1 *(5+x)] = 8 + [-x + 1*(5+x)]
= 8 + [-x + 5 + x]
You can drop the parenthesis around the 5+x because there is
nothing else that can be done there.
Step 4: Start at the beginning of PEMDAS to make sure that simplifying didn't change anything since we went through it before. We can see now that there are two like terms in the parenthesis, so we need to combine like terms before we can move on. Remember, like terms have the same variable (or none at all) and the same exponent (or none at all).
8 + [-x + 5 + x] <- -x +x = 0
= 8 + [0 + 5] <- 0 and 5 are also like terms and can be combined
= 8 + 5
Step 5: Simplify.
8 + 5
= 13
I hope this was helpful!!
Patty
