Question 186141
We have the linear equation:

57 - w = 20

Subtract 57 from both sides of the linear equation.

Doing so, we get: -w = -57 + 20

Simplifying the right side, we get -37 and our linear equation now looks like this:

-w = -37

Divide both sides by the coefficient of w, which happens to be -1.

Yes, there is a -1 there.  In math, we never write -1w or 1w (never place a number 1 or -1 in front of a variable).  It is there invisibly.  Is this clear?

Back to your question.

-w = -37

w = -37 divided by -1

w = 37

Is this clear?

Feliz