Answer:
Let the weight of the leader dog = X
Then Darlene's dog weighs = 5X ( fives times as much)
Now add both together to equal 84 pounds:
5X + X = 84
Simplify:
6x = 84
Divide both sides by 6:
x = 84 / 6
x = 14
The leader dog weighs 14 pounds.
Darlene's dog weighs 70 pounds.