Answer:
3 seed packets
Explanation:
So first, we know that for every 1 seed packet Owen uses, he can grow 2 plants. The ratio is 1:2 (1 = # of seed packets, 2 = # of plants). So now, we need to figure out how many seed packets he needs to have a total of 9 plants. Before we calculate anything, we need to subtract 3 from 9 because it is the total number of plants, and we get 6 plants. To calculate the amount of seed packets Owen needs, we need to get the ration (1:2) and multiply it by 3 on both sides because we need 6 plants. 2 × 3 = 6, and 1 × 3 = 3. The ratio is 3:6. So now we know that Owen needs 3 more seed packets in order to have a total of 9 plants in his backyard. :)