Final answer:
When using the method of substitution to solve the system -3x-2y=1 and -x+y=3, we can express y in terms of x and substitute it into the first equation, resulting in -3x -2(x+3) = 1.
Step-by-step explanation:
When using the method of substitution to solve the system -3x-2y=1 and -x+y=3, we want to express one variable in terms of the other in order to substitute it into the other equation.
In this case, we can express y in terms of x from the second equation: y = x + 3.
Now we can substitute this expression for y into the first equation: -3x - 2(x+3) = 1. Simplifying this equation gives us -3x -2x - 6 = 1, which is option c) -3x -2(x+3) = 1.