Yes because when you add a negative, its like subtracting. but when you subtract a negative it becomes a positive, so if you had 10-(-5) it would be the same as 10+5. In this situation, -10+(-5) is the same as -10-5 which makes it equal. Hope this helps.
Yes because they both equal -15 because you actually turn -10+(-5) into a subtraction problem because if there's a + and -, you actually turn it into a minus and the answer is -15.
