1.What are the x-intercepts of the parabola defined by the equation y=2x2–8x –90?Indicate allx-intercepts.
因为求x轴截距，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. 所以选C,G.
2.When the positive integer dis divided by 12, the remainder is 5. What is the remainder when d is divided by 8 ?
3. The interior dimensions of a rectangular tank are as follows: length 110 centimeters, width 90 centimeters, and height 270 centimeters. The tank rests on level ground. Based on the assumption that the volume of water increases by 10 percent when it freezes, which of the following is closest to the maximum height, in centimeters, to which the tank can be filled with water so that when the water freezes, the ice would not rise above the top of the tank?
4. In a certain sequence of numbers, each term after the first term is found by multiplying the preceding term by 2 and then subtracting 3 from the product. If the 4th term in the sequence is 19, which of the following numbers are in the sequence? Indicate all such numbers.
正确答案：A C E