每日一练：ACT数学练习题

　　ACT数学成绩有所提高，坚持每天做练习是十分必要的，就像这样每天完成ACT数学题，并进行总结，日积月累，成绩就会有明显地提高。下面我们来看一下两道ACT数学题。

　　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。

　　以上就是小编为大家介绍的关于ACT数学练习题。更多ACT考试难度、ACT写作时间等问题，可以咨询我们。