帮忙

zjf

[fly]HELP：
R 方法和 S 方法不同在R方法下的6，24分别对应S方法下的30，60，R和S成LINEAR关系。问要得到S方法下的100，应在R方法下是多少？

答案是48，可我没思路。
谢谢

wuzi

[em06][em06]
r方法对应坐标系x轴，s方法对应y轴,该题已知条件两点坐标(6，30）（24，60），求y=100时，x=多少？
解：根据两点式直线方程（y-y1)/(x-x1)=(y1-y2)/(x1-x2)
    (y-30)/(x-6)=(60-30)/(24-6)
     得3y=5x+60,代入y=100,
     得x=48.

iamf

u can also solve this problem as following:
'cause R and S are linear.. then we can suppose R=aS+b
we know (6,30) (24,60).
then we have a=0.6 b=-12

if S=100, R=48

zjf

Thank you very much for helping me,i will take the test next week, but still think there are too much to be review, i can not even know which part should i pay more attention to in only the limit days. some opinions?

maryland

复习的方向应该是针对自己的弱点做最后的强化训练。最后几天则可以看看最近1个月的JJ。