A man is painting a building 20 meters high. He leans an 12 meter ladder against the building. The ladder is 4 meters away from the building. If the man is 1.86 meters tall, approximately how high will he be able to reach on the building to paint if he is standing on at the top of the ladder.

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.