Answer:john weighs 375 pounds.
Karen weighs 125 pounds
Step-by-step explanation:
Let x represent the weight of John.
Let y represent the weight of Karen.
John weighs three times as much as Karen. This means that
x = 3y
Two times John's weight plus Karen's weight is 875 pounds. This means that
2x + y = 875 - - - - - - - -1
Substituting x = 3y into equation 1, it becomes
2 × 3y + y = 875
6y + y = 875
7y = 875
y = 875/7 = 125
Substituting y = 125 into x = 3y. It becomes
x = 3 × 125 = 375
