5x-6y=-32 and 3x+6y-48 solve by substitution

Mrs. gehrke said cheddar weighs 16.8 pounds. he actually weighs 15.2 pounds. what is the percent error?

Is it greater than or less than7*3_9*2

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