Parentheses in simple Order of Operations: Only addition and subtraction

Let's begin by simplifying the expression following the order of operations.

P- PARENTHESES

E-EXPONENTS

D-DIVISION

A-ADDITION

S-SUBTRACTION

$18-(3+3)= \\ 18-6= \\ 12$

Therefore the correct answer is answer D.

First, solve the expression inside the parentheses:
$8 + 5 = 13$

Then subtract from 25:
$25 - 13 = 12$

First, solve the expression inside the parentheses:
$10 + 7 = 17$

Then subtract from 30:
$30 - 17 = 13$

First, we solve the exercise:

$4+7-3+1-5 =$

According to the rules of the order of operations, we solve the exercise from left to right:

$4+7=11$

$11-3=8$

$8+1=9$

$9-5=4$

Now we solve the exercise:

$4+(7-3+1-5) =$

According to the rules of the order of operations, we first solve the parentheses and then we will join:

$(7-3+1-5)=$

$(4+1-5)=$

$(5-5)=0$

$4+0=4$

Therefore:

$4=4$