Easy Algebra Step-by-Step

60 Easy Algebra Step-by-Step

d. 815

Step 1. Absolute value bars are a grouping symbol, so do 815 fi rst.

8157

Step 2. Evaluate − 7.

= 7

e. 36 + 64

Step 1. The square root symbol is a grouping symbol, so do 36 + 64 fi rst.

36 += 6464 100

Step 2. Evaluate 100.

= 10

PEMDAS

You must follow the order of operations to simplify mathematical expres-

sions. Use the mnemonic “Please Excuse My Dear Aunt Sally”—abbreviated

as PE(MD)(AS) to help you remember the following order.

Order of Operations

1. Do computations inside Parentheses (or other grouping symbols).


2. Evaluate Exponential expressions (also, evaluate absolute value,
   square root, and other root expressions).


3. Perform Multiplication and
   Division, in the order in which
   these operations occur from left
   to right.


4. Perform Addition and
   Subtraction, in the order in
   which these operations occur
   from left to right.

P

8158 ≠+ 8 − 15. 8157 , but

81588 + 15 = 23. Not performing

the addition, 815 , fi rst can lead to an

incorrect result.

36 +≠ 6464 36 + 64. 36 += 6464 10 ,

36 += 6464 688 = 14. Not performing the addition,

36 + 64 , fi rst can lead to an incorrect result.

In the order of operations, multiplication

does not always have to be done before

division, or addition before subtraction.

You multiply and divide in the order they

occur in the problem. Similarly, you add

and subtract in the order they occur in the

problem.