The Ashland High School Science Department is purchasing new earth science and physics textbooks this year. Ms. Eaton has requested 97 earth science textbooks and 71 physics textbooks for all of her classes, which costs the department a total of $7,624. Mr. Newman has asked for 95 earth science textbooks and 93 physics textbooks, which will cost a total of $8,640. How much do the textbooks cost?

Astudent is determining the influence of different types of food on the growth rate of spiders. she feeds one group of spiders two caterpillars twice a week. the other group received similarly-sized beetles twice a week. she records the amount of time required for individuals to reach sexual maturity. her hypothesis is that the spiders feeding on caterpillars will have a faster growth rate because caterpillars have a higher protein content compared to beetles. in this experiment, what is the dependent variable? spiders assigned to different feeding groups. time required to reach sexual maturity number of prey items fed twice a week. growth rates of each group.