Help please explain answer.

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9

Which statement explains how you could use coordinate geometry to prove the opposite sides of a quadrilateral are congruent? a. use the slope formula to prove the slopes of the opposite sides are the same. b. use the slope formula to prove the slopes of the opposite sides are opposite reciprocals. c. use the distance formula to prove the lengths of the opposite sides are the same. d. use the distance formula to prove the midpoints of the opposite sides are the same.