Gabriela is building a brick wall. each row of bricks is 6.5 cm 6.5cm6, point, 5, start text, c, m, end text tall except that the top row is 1 cm 1cm1, start text, c, m, end text shorter because it has no mortar. she wants the wall to be 259 cm 259cm259, start text, c, m, end text tall. which equation can we use to determine r rr, the number of rows of bricks gabriela needs in her wall?