HELP! Basic Algebraneed help quick 6(c+5) - 2c= 56-9c What is c

-1/2x + 6x - 2 = 20 What is x

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

Which has the greater energy, light of wavelength 519 nm or light with a frequency of 5.42 x 10^8 sec^-1?

If you were constructing a triangular frame, and you had wood in the length of 4 inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood?