BODMAS or PEMDAS tells us that multiplication must be done before addition and subtraction. So we must first calculate 6×8=48 and 2×5=10, and we place these products back in the expression:
-8+48-10=30. So the answer is 30.
We could rewrite this as 48-8-10 and carry out the sum from left to right:
48-8=40 and 40-10=30.