a hot air ballon leaves the ground in climb to 170 feet if it than climbs an additional 80 feet how far above is the ground is the ballon
To answer this question, look at the words that are being used. The balloon is starting at the ground. That is the like starting with 0. It climbs 170 feet, so that is adding 170 feet. Then it climbs another 80 feet, so it is going up, or adding again.
That means that you are starting with 0 (the balloon is on the ground), + 170 (it went up 170 feet), + 80 (it went up another 80 feet), or
would be the equation to solve to get your answer.
I hope this explains how you would get your answer.