9 ) Jason bought 9 new baseball trading cards to add to his collection. The next day his dog ate half of his collection. There are now only 31 cards left. How many cards did Jason start with ?

He started with 53 cards

Step-by-step explanation:

He has 31 now

If 31 is half of what he had, then we need to double it

31 x 2 = 62

If he had bought 9, then we need to do the opposite

62 - 9 = 53

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a