The power of linearity is F=k1+k2 if I come across f of x, y, z equals k1 plus k2, if it is a linear equation, I don't have to go and solve it all over again.

线性的威力是,一个方程，如果它是个线性方程，那么我就不用再去解他了。

麻省理工公开课 - 固态化学导论课程节选

See, I've defined f of x to be a function x=x+1 that takes a value of x in, changes x to x+1, x and then just returns the value.

我定义了f是一个函数,输入x，让，然后输出。

麻省理工公开课 - 计算机科学及编程导论课程节选