Answer:
B. 10 minutes
Explanation:
Let x represent the number of minutes that a sea otter can hold its breath. A hippopotamus can hold its breath for 5 minutes longer than x. So, the equation would be:
x + 5 = 15
Subtract 5 from both sides.
x + 5 = 15
x + 5 - 5 = 15 - 5
x = 10
A sea otter can hold its breath for 10 minutes.
Hope that helps.