2018年ACT数学练习题（3）

　　今天课窝小编为大家准备了ACT数学真题练习，希望能够对你有所帮助，顺利通过2018年的ACT考试，早日实现自己的留学梦!

　　1. 3x3·2x2y·4x2y is equivalent to:

　　A. 9x7y2

　　B. 9x12y2

　　C. 24x7y2

　　D. 24x12y

　　E. 24x12y2

　　解析：The correct answer is C. To find an equivalent expression, you can multiply the constants (3·2·4), combine the x term (x3x2x2 → x3+2+2 → x7, because when you have a common base you use the base and add the exponents), and combine the y terms (y·y → y1y1 → y1+1 → y2). The result is 24x7y2.

　　正确答案选C。常数相乘(3·2·4)，合并x项(x3x2x2 → x3+2+2 → x7) 和y项(y·y → y1y1 → y1+1→ y2)，结果为24x7y2。

　　2. Mr. Dietz is a teacher whose salary is $22,570 for this school year, which has 185 days. In Mr. Dietz's school district, substitute teachers are paid $80 per day. If Mr. Dietz's takes a day off without pay and a substitute teacher is paid to teach Mr. Dietz's classes, how much less does the school district pay in salary by paying a substitute teacher instead of paying Mr. Dietz's for that day?

　　F. $ 42

　　G. $ 80

　　H. $ 97

　　J. $105

　　K. $122

　　解析：The correct answer is F. To find Mr. Dietz's pay per day, you can divide his salary, $22,570, by the number of days he works,185. His pay per day is 22570/185, or $122. When Mr. Dietz takes a day off without pay and the school pays a subsititute $80, the school district saves the difference in these amounts, 122-80, or $42.

　　正确答案选F。先算出Dietz先生每天的平均工资，用22570除以185(可用计算器)，即122美元。再用122美元减去学校需要支付临时老师的费用80美元，即可算出学校结余的费用，为42美元。

　　今天上海ACT培训小编就和大家分享以上ACT课程内容，希望大家能够熟练掌握，对同学们2018年ACT考试会有所帮助的，小编会继续更新ACT真题，ACT数学以及ACT写作等相关内容。