
Navin Kumar B. answered 02/28/23
Biology,Statistics & Psychology tutor with Interdisciplinary expertise
Let's assume Abby has A dollars and Ben has B dollars.
According to the problem statement:
If Abby gives $10 to Ben, then Abby will have the same amount of money as Ben. This can be represented by the equation: A - 10 = B + 10 or A - B = 20.
If Ben gives Abby $20, then Abby will have 4 times as much money as Ben. This can be represented by the equation: B - 20 = 4(A + 20) or B - 20 = 4A + 80.
We can solve for one variable in terms of the other from the first equation:
A - B = 20
A = B + 20
Substituting this expression for A into the second equation gives:
B - 20 = 4(B + 20) + 80
B - 20 = 4B + 100
-3B = -120
B = 40
Therefore, Ben has $40. Using the first equation to solve for A, we get:
A - B = 20
A - 40 = 20
A = 60
Therefore, Abby has $60.