Isolating a variable in two equations is easiest when one of them has a coefficient of 1. Let's say we have the two equations:
3A - B = 5
2A + 3B = -4
and we want to isolate one of the variables so that it appears by itself on one side of the equation. Which of the following is an equation with one of the above variables isolated?
Now that we have one of the variables from Part A isolated and written in terms of the other variable, we can now substitute this into the other of the two original equations. Which of the following options represents this?