2x+y=8 and 6x-y=5...which variable should be eliminated and why

Which of the following statements is not true? a. parallel lines are lines in the same plane that never intersect. b. congruent figures have the same shape and same size angles and sides. c. similar figures must have the same shape and the same size. d. a rotation is when you turn a figure around a certain point.

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15