Find the sum of the following expression -5y-4 and -10-6y

The suare root of 9x plus 7 plus the square rot of 2x equall to 7

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

Find the circumference of a pizza with a diameter of 10 inches round to the nearest tenth