Simplify "6+2y-3+4y"​

Askyscraper is 396 meters tall. at a certain time of day, it casts a shadow that is 332 meters long.at what angle is the sun above the horizon at that time?

Angle that produces maximum distance

Given: m< ade = 60° and m< cdf = (3x + 15) prove: x = 15 what is the missing statement and the missing reason in step 5?