While Flinn was starting the fire, his friends were collecting firewood. Flinn has 5 sticks. If he puts 3 sticks in the fire every minute, and his friends bring 7 sticks every minute, how many minutes will they need to make a pile of 45 sticks next to their fire?

Respuesta :

7m - 3m + 5 = 45

4m + 5 = 45

45-5 = 40

4m = 40

40/4

m = 10 minutes