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

$x = \frac{462}{2}$
$x = 231$
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