What are the x-intercepts of the parabola defined by theequation y =2x2–8x –90?
    Indicate allx-intercepts.
    A. -10
    B. -9
    C. -5
    D. -4
    E. 4
    F. 5
    G. 9
    H. 10
    解析：C, G
    因?yàn)榍髕軸截距，所以y=0，所以2x2–8x –90=0，所以(2x+10)(x-9)=0. 所以x= -5, 或者x=9. 所以選C,G.
    The system of equations has how many solutions?
    3x - 6y = 9
    2y - x - 3 = 0
    A. None
    B. Exactly 1
    C. Exactly 2
    D. Exactly 3
    E. Infinitely many
    解析：B
    因?yàn)?x - 6y = 9，所以x-2y=3. 因?yàn)?y - x - 3 = 0，所以2y-x=3. 所以x-2y=2y-x. 所以x=0,y=0.只有這一種可能。所以選B.
    If x=3k/√5 and k>0， which of the following must be true?
    解析：C
    因?yàn)?，所以x=(3√5)/5 k，所以k
    For the 3 numbers in a certain list, the average (arithmetic mean) and the median are equal to 16. If the greatest number in the List is 14 greater than the least number, what is the greatest number in the list?
    解析：23
    設(shè)最小的數(shù)為x,因?yàn)榈臄?shù)比最小的數(shù)大14，所以的數(shù)為x+14.因?yàn)檫@三個(gè)數(shù)的平均值為16，且中間的數(shù)值為16，所以(x+16+(x+14))/3=16.所以x=9. 所以的數(shù)為9+14=23.
    When thepositive integer dis divided by 12, the remainder is 5. Whatis the remainder when d is divided by 8 ?
    A. 1
    B.3
    C.5
    D.6
    E.7
    解析：A
    正整數(shù)d被12整除后余5，因此正整數(shù)d為12*5+5=65. 所以〖65〗^2除以8等于528余1.所以選A。
    In agroup of 60 people, the average (arithmetic mean) age of the 40 females is 60,and the average age of the 20 males is 70.
    Column A ColumnB
    Average age of all 60 people 65
    A. Thequantity in Column A is greater
    B. Thequantity in Column B is greater
    C. The twoquantities are equal
    D. Therelationship cannot be determined from the information given
    解析：
    因?yàn)橐还灿?0個(gè)人，40個(gè)人的平均年齡是60歲，20個(gè)人的平均年齡是70歲。所以這60個(gè)人的平均年齡為(40*60+20*70)/60=63.33. 63.33<65,所以B更大。所以選B。