数学独家2.6-2.9全程班.pptx

GRE Quantitative Reasoning;注意文字转换为数学方程时候的过程;Ellen has received the following scores on 3 exams:82,74, and 90. What score will Ellen need to receive on the next exam so that the average (arithmetic mean)score for the 4 exams will be 85? In a driving competition, Jeff and Dennis drove the same course at average speeds of 51 miles per hour and 54 miles per hour, respectively. If it took Jeff 40 minutes to drive the course, how long did it take Dennis? If an amount P is to be invested at an annual interest rate of 3.5 percent, compounded annually, what should be the value of P so that the value of the investment is 1,000 at the end of 3 years? A college student expects to earn at least $1,000 in interest on an initial investment of $20,000. If the money is invested for one year at interest compounded quarterly, what is the least annual interest rate that would achieve the goal?;Algebra(代数)----- 07 Coordinate Geometry（几何坐标）; 2. 知识点讲解.;graphs of functions y=kx+b 的图像是一条直线，斜率为k, y轴的截距为b（截距可正可负可为0） y=ax2+bx+c , 其中a≠0的图像是一个抛物线parabola 如y=x2-2x-3的顶点vertex是（1, -4），x=1是对称轴line of symmetry，开口向上opens upward (x-a)2+(y-b)2=r2的图像是一个圆circle，圆心center为（a, b), radius半径为r y=f(x)和y=g(x)的图像交点就是f(x)=g(x)的解 上加下减左加右减;第二节 Algebra(代数)----- 例题综合练习;In the xy-plane, find the following. (a)Slope and y-intercept of the line with equation 2y+x=6 (b)Equation of the line passing through the point (3,2) with y-intercept 1 (c)The y-intercept of a line with slope 3 that passes through the point (-2,1) (d) The x-intercepts of the graphs in (a),(b), and (c) For the parabola y=x2-4x-12 in the xy-plane, find the following. (a)The x-intercepts (b)The y-intercept (c)Coordinates of the vertex For a given two-digit positive integer, the tens digit is 5 more than the units digit. The sum of the digits is 11. Find the integer. 7. If the ratio of 2x to 5y is 3 to 4, what is the ratio of x to y?;8. n is a positive integer. Quantity A