Did somebody say you're supposed to draw the graph of the equation ? Is that the assignment ?
OK. Just like every other equation you need to graph, get it in the standard form, where 'y' is all alone on one side, and everything else is on the other side. When you do that, you'll be able to spot the slope and y-intercept of the line, or get some points, or whatever you want.
4y + 12 = 0
Subtract 12 from each side: 4y = -12
Divide each side by 4: y = -3
There's the equation you can handle. The y-intercept is -3, and the slope is zero.
Would you like some points ? OK. Pick a couple of values for 'x', and calculate the value of 'y' for each one:
The first value I picked for 'x': x = 72 The equation is y=-3, so when x=72, y=-3. The point is (72, -3)
The second value I picked for 'x' is: x = 1 The equation is y=-3, so when x=1, y=-3. The second point is (1, -3).
The third value I picked for 'x' is 4 billion. The equation is y=-3, so when x=4 billion, y=-3. The third point is (1, -3).
Do you see what's going on here ? Your original equation didn't even have 'x' in it, so we could tell right away that when the graph is drawn, the value of 'y' at every point can't depend on 'x'.
When we simplified the equation and got it in standard form, we found that the slope of the graph is zero. That means the graph doesn't rise or fall ... it's just a horizontal line. Sure enough, the height of points on the line doesn't depend on 'x'. The value of 'y' at every point on the line is -3 .
The sum of a geometric series is, , with a being the start point and r is the common ratio. We can also use the following formula to make life easier , a is your start point, r is the common ratio, and n is the number of terms, which in our case is S7.
