First, convert that into a y=mx+b form.
Move the x to the other side so y is the only thing on the left. Since you moved it to the other side of the equal sign, be sure to make that number negative (the opposite sign)
Now… you have 4y=-3x+28
Let’s get y by itself. Since you’re multiplying 4 and y, you divide everything by 4 to get your y.
That leaves you with y=-3/4x+7.
We are looking at slope, which is your m in the y=mx+b form.
That is -3/4. The answer is the last square.