Answer:
They practiced a total of 75 math facts in all!
60 + 15 = 75 :D
Let the positive number be

The expression is

⇒ expanding the bracket gives,

⇒ rearranging to equate one side to zero

⇒ Dividing each term by 7 to simplify

⇒ Factorising gives


and

Hence, the first number is -5 and the second number is 3
Plant B is the most proportional because 18+18+18=54 and plant A described 18+18+20 so plant b grew exactly 18 inches per week which is proportional but plant A did not grow proportionally so The situation that presents a proportional relationship between the plants height and number of weeks would be plant B