You can name Plane P, many different ways,
Assuming you are asking this out of a textbook staring at a figure of a Parallelogram, their are probably points inside that shape and the way you would name it would be naming using any three points in the plane that are NOT on the same line in any order. <span />
Answer:

Step-by-step explanation:
Let
denotes number of pencils, markers, erasers respectively.
For Andrea:

For Justin:

For Virginia:

On subtracting equations (i) and (ii), we get

Put
in equation (i)

Put
in equation (iii)

Multiply equation (iv) by 5 and equation (v) by 6 and then subtract both the equations.

Put
in equation 

Put
in equation (i)

Take your x values in each coordinate and subtract 2, and take your y values and subtract 1.
Q (0-2), (-1-1)
= (-2,-2)
D (-2-2), (2-1)
= (-4, 1)
V (2-2), (4-1)
= (0,3)
J (3-2), (0-1)
= (1,-1)
You can also draw it on a graph and then translate all coordinates 2 units left and 1 down to see the end results.
I think not because a square has four sides and a triangle has three.
9514 1404 393
Answer:
2 nickels, 9 dimes
Step-by-step explanation:
When there are a number of overlapping shaded areas on the graph, I find it convenient to use the reverse of the inequalities. That makes the <em>unshaded</em> area the solution space. Here, the vertices of the triangular solution space are ...
(2, 9), (2, 13), (6, 9)
Any of the grid points within (or on) this triangle is a possible solution. One of them is (2, 9) corresponding to 2 nickels and 9 dimes.
__
Three solutions are shown:
(x, y) = (2, 9), (3, 10), (4, 11)