Which best describes the sides of any trapezoid? a. all sides are the same length. b. only one pair of sides is parallel. c. both pairs of opposite sides are parallel.

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.