Final answer:
To form opposite terms for the x-variable in the given equations, multiply the first equation by -1 and leave the second equation unchanged.
Step-by-step explanation:
To form opposite terms for the x-variable in the given equations, we need to multiply each equation by a number that produces opposite coefficients for x.
Let's start with the first equation, 3x + 4 = -3y.
To make the coefficient of x positive, we can multiply the entire equation by -1. This gives us -3x - 4 = 3y.
Now, let's move on to the second equation, -3x + 9 = -3y.
Here, the coefficient of x is already negative, so we can multiply the equation by 1 to keep the coefficient the same.
This gives us -3x + 9 = -3y.