The student council at Greenwood High School is selling T-shirts for $20 apiece. Their costs are $5 per shirt, plus $45 for supplies. Selling a certain number of shirts will allow the student council to cover their costs. How many shirts do they need to sell to break even? How much in costs will they have incurred at that point?

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.

How much money does ron have left each month after his fixed expenses? ron graduated from college five years ago. he recently bought a house, but shares it with a housemate who pays him $800 a month for rent and utilities. ron is putting a budget worksheet together so he will have a better idea of where his money is going and where he can save. enlarge

Of . 3x+4y+4z=4, 5x+7y+3z=5 4x+5y+7z=7