Which line shows the first error in the solution?

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

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?

Asquare and an equilateral triangle have the same perimeter. each side the triangle is 4 inches longer than each side of the square. what is the perimeter of the square