Use substitution to solve. 2x2 = 5 + y
4y = -20 + 8x2
Solve the first equation for y and substitute it into the second equation. The resulting equation is
8x2 - 20 = -20 + 8x2v
The system has

Grace is standing 18 feet from a lighthouse and kelly is standing 10 feet from grace. the angle that grace looks up to see the top of the lighthouse is 45°. the angle that kelly looks up to see the top of the lighthouse is y°. find the height, h, of the lighthouse. find the angle, rounded to the nearest tenth of a degree, in which kelly looks up to the top of the lighthouse. to the nearest tenth of a degree, find the value of x° . in two or more sentences, explain your calculations