Need help can y’all help me?

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

Fill in the blank 1. a rhombus is a rectangle a) always b) sometimes c) never 2. a square is a quadrilateral a) always b) sometimes c) never 3. a trapezoid is a kite a) always b) sometimes c) never 4. a quadrilateral is a kite a) always b) sometimes c) never 5. a square is a rhombus a) always b) sometimes c) never 6. a parallelogram is a rectangle a) always b) sometimes c) never

Zahra wants the equation below to have an infinite number of solutions when the missing number is placed in the box.