This expression is about adding two terms: One term is 4 and the other term is (6-2).
To evaluate this expression, first you have to calculate the term in parenthesis. So 6-2 gives you 4. So the expression now becomes 4+ 4. This is a simple addition. So 4+4 gives you 8. This is your answer.
Please note that when an expression contains a number of different signs , then you follow this order for calculation: parenthesis first, then multiplication, division, addition and subtraction.