A farmer has 280 acres of land on which he plans to plant two different crops, crop A and crop B. For each acre of crop A he plants, his expenses are $25, and for each acre of crop B, his expenses are $30. The farmer has a limit of $10,000 for the expenses of planting the 280 acres. If a represents the acres of crop A and b represents the acre of crop B that the farmer plants, which of these represent the limits of a and b?

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