The sum of 15 and the product of 5 and v

Which of the following of the following sets of side lengths could not form a triangle?

The triangles are similar. what is the value of x? show your work.

Aplane flies around trip to philadelphia it flies to philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour if the total trip takes 6.5 hours how many miles does the plane fly round trip