SOLUTION: Bruce bought two books. One book cost four dollars more than three times the other. Together, the two books cost him $72. What is the equation for the problem?

Click here to see ALL problems on Linear-equations

Question 1044196: Bruce bought two books. One book cost four dollars more than three times the other. Together, the two books cost him $72. What is the equation for the problem?
Found 3 solutions by reviewermath, Boreal, addingup:
Answer by reviewermath(1029)   (Show Source):
You can put this solution on YOUR website!
Q: Bruce bought two books. One book cost four dollars more than three times the other. Together, the two books cost him $72. What is the equation for the problem?
Solution:
Let x = cost of the cheaper book
So (4 + 3x) = cost of the other book
The equation is

Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website!
cost of book a=x
cost of book b=3x+4
Their sum is $72.
The equation is x+(3x+4)=$72 ANSWER
(x=$17;3x+4=$55)

Answer by addingup(3677)   (Show Source):
You can put this solution on YOUR website!
let one book be x. Then, the problem says the other will be:
3x+4
Put it all together:
x+3x+4 = 72
4x = 68
x = 17
Happy learning,
John