A textbook store sold a combined total of 327 psychology and history textbooks in a week. The number of history textbooks sold was 75 less than the number of psychology textbooks sold. How many textbooks of each type were sold?

Respuesta :

Answer:

201 psychology textbooks

126 history textbooks

Step-by-step explanation:

We let the number of psychology books be p, and

number of history books be h

Thus we can write 2 equations as:

1. p + h = 327

2. p - 75 = h

Now, we put equaiton 2 into equation 1 and solve for p first:

p + h = 327

p + (p-75) = 327

2p = 327 + 75

2p = 402

p = 402/2 = 201

So, 201 psychology textbooks. Now, we know p - 75 = h, hence

201 - 75 = h

h = 126

So, 126 history textbooks