Abed says he has written a system of two linear equations that has an infinite number of solutions. one of the
equations of the system is y = 3.x - 1. which could be the other equation?
y = 3.x + 2
3x - y = 2
3.x - y = 1
3x + y = 1

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.