Typing speed is calculated using the formula s = (w-10e) / 5 solve the formula for e in terms s and w

So you have s = (w-10e) / 5

To get rid of the 5, multiply the equation by 5, then to the other side.

So now it is 5s=w-10e

Now subtract w. So its now 5s-w=-10e

Now divide the - 10. So now it is e = (5s-w) / - 10

And it will not simplify because the s and w have different coefficients.