Which set of expressions are not equivalent? (9 c + 12) - c - 3 and 8 c + 9
4 c - 2 c - 3 and 2 c - 3
5 c - 2 c + 8 - 4 and 3 c + 4
0.5 + (10 c + 8) and 5 c - 4

The line containing the midpoints of the legs of right triangle abc where a(-5,5), b(1, 1), and c(3, 4) are the vertices.

Acar travels at an average speed of 56 miles per hour. how long does it take to travel 196 miles

The perimeter of ? cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.