Finding lengths. Write similarity statements for three triangles in the diagram. then find the given length. Find HF HELP ME PLEASE

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

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

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?