Answer:176 psychology textbooks and 98 Biology textbooks were sold.
Step-by-step explanation:
Let x represent the number of psychology textbooks that were sold.
Let y represent the number of biology textbooks that were sold.
textbook store sold a combined total of 274 psychology and biology textbooks in a week. This means that
x + y = 274 - - - - - - - - - - -1
The number of psychology textbooks sold was 78 more than the number of biology textbooks sold. This means that
x = y + 78
Substituting x = y + 78 into equation 1, it becomes
y + 78 + y = 274
2y = 274 - 78
2y = 196
y = 98
x = y + 78 = 98 + 78
x = 176
Each person payed $175
First add the cost up:
$900 on transportation + $500 hotel room= $1400 total
8 people paying $1400 means divide 1400 by 8 to see how much one person payed.
1400/8 = 175
Each person payed $175
Answer: x = -8
Step-by-step explanation: Isolate the variable by dividing each side by factors that don't contain the variable.
Hope this helps you out! ☺