A textbook store sold a combined total of 480 physics and history textbooks in a week. The number of physics textbooks sold was three times the number of history textbooks sold. How many textbooks of each type were sold?

120 history textbooks

360 physics textbooks

Step-by-step explanation:

Physics textbooks = 3 times the amount of history textbooks

History textbooks = x

Physics textbooks = 3x

480 = x + 3x

= 4x

480/4 = x

x = 120

120 history books sold

480-120 = 360

360 physics textbooks sold

btw sorry if I didn't give enough working or help you understand it I'm not great at this kind of thing

Paula charges more per hour but has a lower travel fee.

Step-by-step explanation:

The equation that represents Diana's situation is

x represents the number of hours of classes

y represents the total cost.

Paula finds her graph is shifted below Diana's line, and her line is also steeper than Diana's line.

So, the answer is : Paula charges more per hour that makes the graph more steeper, and has a lower travel fee that results in graph shifting below Diana's line.