Normally, if I tell you 3x + 4y = 6, and 9x + 6y = 14, you know how to solve it.

一般来说,如果我给你两个方程 3x + 4y = 6,和 9x + 6y = 14,你们肯定会解

耶鲁公开课 - 基础物理课程节选

If I told you 3x + 2y = 9 and 4x + 6y = 6, you certainly know how to solve for x and y, right?

如果我给出 3x + 2y = 9,和 4x + 6y = 6 这两个方程,你们肯定知道怎么解出 x 和 y,对吧

耶鲁公开课 - 基础物理课程节选

If you are describing a particle with location R, the vector we use typically to locate a particle, R then R is just i times x + j times y, because you all know that's x and that's y.

如果你要描述一个位移为 R 的质点,这个矢量一般用表示质点 R 的位移,R 可表示为 i ? x + j ? y,显然你们都知道这段是 x,那段是 y

耶鲁公开课 - 基础物理课程节选