we have
6+6×8-5÷3+12
so
Applying PEMDAS
P ----> Parentheses first
E -----> Exponents (Powers and Square Roots, etc.)
MD ----> Multiplication and Division (left-to-right)
AS ----> Addition and Subtraction (left-to-right)
step 1
Multiplication
6x8=48
substitute
6+48-5÷3+12
step 2
Division
5÷3=5/3
substitute
6+48-(5/3)+12
step 3
Addition
6+48=54
54-5/3+12
step 4
S