54 square feet
9x6 = 54
B x h = a
Base x height = area
Y=2x^3 is nonlinear, since it's a cube equation. y=x+5 is linear, because it's a line with y intercept (0,-5) and slope 1. y=\sqrt(x-5) is nonlinear, because it's a quadratic equation when reversing x and y. 5x+5y=25 is equal to x+y=5 ot y=-x+5, which is also linear. y=x^2/2 is a quadratic equation, so it's nonlinear.
Answer:
The equation, y=3x-5 is in y=mx+b format. The b, or -5 in this case, tells you what the y intercept is, or in this case, your starting point. This means your first point will be at (0,-5). The mx, or 3x in this case, tell us how much to move up and how much to move sideways. 3x is equal to 3/1x and the 3/1 tells us the rise/run. Rise being how much to go up or down and run being how much to go to the left or right. So in 3x, the rise is 3 and the run is 1. So you will go 3 up on the y axis and 1 to the right on the x-axis. So your next point will be (1, -2) and the point after that will be (2, 1) and so on!
hope this helped!
