Question 272223
a = money that andy has.
b = money that brian has.
c = money that chris has.


a + b = 40
b + c = 62
a + c = 58


use your first equation to solve for b in terms of a.
you get b = 40-a


use your third equation to solve for c in terms of a.
you get c = 58-a


substitute for b and c in your second equation to get:


b + c = 62 becomes:
40-a + 58-a = 62
combine like terms to get:
98 - 2a = 62
add 2a to both sides of this equation and subtract 62 from both sides of this equation to get:
98 - 62 = 2a
combine like terms to get:
36 = 2a
divide both sides of this equation by 2 to get:
18 = a


substitute for a in the first equation to get:


a + b = 40 becomes:
18 + b = 40
solve for b to get:
b = 40-18 = 22


substitute for a in the third equation to get:


a + c = 58 becomes:
18 + c = 58
solve for c to get:
c = 58-18 = 40


your solution should be:
a = 18
b = 22
c = 40


substitute in your original equations to see if these values are good.


original equations are:


a + b = 40
b + c = 62
a + c = 58


These become:


18 + 22 = 40 (true)
22 + 40 = 62 (true)
18 + 40 = 58 (true)


Values are good.


Answer is:


The money that all 3 of them have together is:


18 + 22 + 40 = $80.00


That would be selection b.