Question 13169
You need to first assign variables for the nuts and bolts.  I am going to use N for nuts and B for bolts.

I have added equations to your question to describe the sentences.

Since you know that B = 66N, and you also know that B = 36(N + 20), you can set these two equations equal to one another. Therefore, you get {{{66N = 36(N + 20)}}}.

To solve this, use the distributive property to distribute the 36 across the N+20 to get {{{66N = 36N + 720}}}.  Move 36N to the left side of the equation by subtracting it from both sides of the equation to get {{{30N = 720}}}.  Solve by dividing by 30.  N=24.

To solve for B, plug in N=24 to the first original equation and solve.  {{{B = 66(24)}}}; B = 1,584