Evan has a shell collection. on monday, he found 6 new shells. on tuesday, he gave 9 shells to his friends. after giving the shells away, he had 37 left. how many did he have to start?

40 shells

Step-by-step explanation:

Let Evan has the number of shells on Monday = x

He found 6 new shells.

Now he has the number of shells = (x + 6)

On Tuesday, he gave 9 shells to his friends = (x + 6) - 9

After giving the shells away, he had 37 shells left.

(x + 6) - 9 = 37

x + 6 = 37 + 9

x + 6 = 46

x = 46 - 6

x = 40

Evan had 40 shells at the start.

c. 4 1/4 pounds