Answer:
29 years of experience.
Explanation:
So let's take the expression step by step. Remember that you need to follow the order of precedence here for the operations. Parentheses, exponentials, multiplication, and addition.
-5 + { 4 * 6 + 3 + 1 + [ 3 - ( 4 - 8 ) + ( 3 - 2 ) ] }
-5 + { 4 * 6 + 3 + 1 + [ 3 - ( -4 ) + ( 1 ) ] }
-5 + { 4 * 6 + 3 + 1 + [ 3 + 4 + 1 ] }
-5 + { 4 * 6 + 3 + 1 + [ 8 ] }
-5 + { 24 + 3 + 1 + 8 }
-5 + { 36 }
29
So the teacher has 29 years of experience.
Cheers.