Atextbook store sold a combined total of 323 math and psychology textbooks in a week. the number of psychology textbooks sold was 65 less than the number of math textbooks sold. how many textbooks of each type were sold?

There were 194 math textbooks and 129 Psychology textbooks sold

Step-by-step explanation:

Lets write some equations where M=math books and P= psych books:

1) M+P=323

2) P=M-65

1) Substitute M-65 as P in the first equation:

M+M-65=323

2) Combine alike terms:

2M-65=323

3) Add 65 to both sides:

2M=388

4) Divide both sides by 2:

M=194

5) Now, substitute 194 as M in the second equation:

P=194-65

6) Subtract:

P=129

answer: the correct one is a

step-by-step explanation: