When Mc. Donalds opened their shakes cost 0.20. today they cost 2.19 what is the percent change?

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

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