9. A student obtains marks in mathematics, physics, and biology. The average of his mathematics and physics marks is 15, his average mark for mathematics and biology is 17, and his average mark for physics and biology is 23. If so, what mark does the student obtain from biology?

The functions below show the amount of money bella and sweet t had saved after earning money for doing chores. which description best compares the two functions?

What is the correct decimal form of 12%

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