Question

A textbook store sold a combined total of 438 biology and psychology textbooks in a week. The number of psychology textbooks sold was 76 less than the number of biology textbooks sold. How many textbooks of each type were sold?Number of biology textbooks sold:Number of psychology textbooks sold:

Answer 1

To determine the number of textbooks sold, we use the provided equations: the total amount of textbooks is 438 and the number of psychology textbooks is 76 less than biology textbooks. Solving these, we find 257 biology textbooks and 181 psychology textbooks were sold.

Step-by-step explanation:

The question involves finding the number of biology and psychology textbooks sold when given the total and the difference between the two. Let's denote the number of biology textbooks as B and psychology textbooks as P. It is given that B + P = 438 and P = B - 76. To solve these equations, we can substitute the second into the first:

1. 
   B + (B - 76) = 438
2. 
   2B - 76 = 438
3. 
   2B = 514
4. 
   B = 257

The number of biology textbooks sold is 257. To find the number of psychology textbooks, we subtract 76 from the number of biology textbooks:

1. 
   P = 257 - 76
2. 
   P = 181

The number of psychology textbooks sold is 181.

Answer 2

Number of biology textbooks sold: 257 textbooks

Number of psychology textbooks sold:​ 181 textbooks

Explanations:

Let the total number of biology textbook sold be "a"

Let the total number of psychology textbook sold be "b"

If a textbook store sold a combined total of 438 biology and psychology textbooks in a week, then:

a + b = 438 ................... 1

If the number of psychology textbooks sold was 76 less than the number of biology textbooks sold, then;

b = a - 76 ...................... 2

Substitute equation 2 into 1

a + (a-76) = 438

a + a - 76 = 438

2a = 438 + 76

2a = 514

a = 514/2

a = 257 biology textbooks

From equation 2;

b = a - 76

b = 257 - 76

b = 181 psychology textbooks

Number of biology textbooks sold: 257 textbooks

Number of psychology textbooks sold:​ 181 textbooks