You can put this solution on YOUR website! <---- We start with this. We're going to work on this equation UNTIL we get it to say "x = some number". The very first thing we should do is to bring all the constant terms to one side of the equation and terms with variables to the other side of the equation. This is done by addition and subtraction.
Remember one of the main themes of Algebra: Whatever you do to one side of the equation, you MUST also do to the other side!
So we want the numbers on one side and the terms with variables on the other. The right thing to do is to subtract 91 from both sides. This cancels out the 91 on the left and changes the 112 to a 21. So, now we have:
<---- When you look at this, it's easy to think, hmmm. 3 times what = 21? That would be 7, so x = 7. Actually, what happens in the background is that you divided BOTH SIDES by 3 to finally make the x be lone by itself on one side of the equation.
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