Question

A textbook store sold a combined total of 377 physics and math textbooks in a week. The number of math textbooks sold was 85 less than the number of physics textbooks sold. How many textbooks of each type were sold?

Answer 1

Let the number of Physics textbooks


Then the number of Math textbooks sold

`= x - 85`


Their total equals 377

`x + x - 85 = 377`

Solving the linear equation for x, we have


`2x - 85 = 377`
Adding 85 to both sides will result in

`\rightarrow \: 2x = 377 + 85`


`2x = 462`
Divide by 2


`x = (462)/(2)`

`x = 231`
Hence the Physics textbooks sold is 231.

To find the math textbook sold , substitute 231 into



`= x - 85`
This gives us,

`= 231 - 85 = 146`
Hence 146 math textbooks were sold