We can solve this by setting up a couple of equations.
Let's allow x to represent the number of paperbacks Tim owns, and allow y to represent the number of hardcover books he owns.
Using the information in the question, we can write the equations:
1)
2)
Let's rearrange equation 1 so that it is in standard form:
And then let's multiply equation 2 by 4 so that we can cancel out y when we solve the system of equations:
Then we can add the two equations and solve for x:
1)
+ 2)
------------------------------------
So now we now the number of paperback books Tim has is 357. Let's plug this into one of the original equations to solve for the number of hardcover books (y):
And now we know that Tim owns 90 hardcover books.
Let's allow x to represent the number of paperbacks Tim owns, and allow y to represent the number of hardcover books he owns.
Using the information in the question, we can write the equations:
1)
2)
Let's rearrange equation 1 so that it is in standard form:
And then let's multiply equation 2 by 4 so that we can cancel out y when we solve the system of equations:
Then we can add the two equations and solve for x:
1)
+ 2)
------------------------------------
So now we now the number of paperback books Tim has is 357. Let's plug this into one of the original equations to solve for the number of hardcover books (y):
And now we know that Tim owns 90 hardcover books.