Would you choose to use a hundred chart to solve 90- 80? why or why. not ? if not. which strategy would work better?

Kathy spent 5/8 of her money on books and another 1/6 of her money on stationeries. what fraction of kathy’s money was left?

The sat and act tests use very different grading scales. the sat math scores follow a normal distribution with mean 518 and standard deviation of 118. the act math scores follow a normal distribution with mean 20.7 and standard deviation of 5. suppose regan scores a 754 on the math portion of the sat. how much would her sister veronica need to score on the math portion of the act to meet or beat regan's score?

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?