Answer:
120 pounds
Step-by-step explanation:
We can use systems of equations to solve this problem. Assuming j is Jim's weight and b is Bob's weight, the equations are:
j + b = 180
b - j = 1/2b
Let's get b - j = 1/2b into standard form (b, then j, then the equal sign, then the constant.)
Now we can solve using the process of elimination.
Now we know how much Bob weighs, for fun, let's find Jim's weight by substituting into the equation.
So Bob weighs 120 pounds and Jim weight 60 pounds.
Hope this helped!