Explain how to graph 2x plus y equals 4?

Answer 1

2x + y = 4 can also be written y = -2x + 4. There are many methods to graphing linear equations. Here is my favorite: because there is only one variable (x) raised to the first power (x1 even though we don't often write it this way), we know that the graph is a straight line. So we need only find two points that lie on the graph and draw the straight line that runs through (and beyond) them.

So plug in two different values for x and see what y= at these values. For instance, when x = 0, y = -2(0) + 4 = 4. So plot the point (0, 4) on your two-dimensional coordinate plane.

Another x value: when x = 1. Plug that into the equation y = -2(1) + 4 = 2. So the point (1, 2) should be on the graph. A straight line through these two points gives you the graph of the equation.

*Another method is to find just one point on the graph, say (0, 4) as we did above, then use the slope (the m in y = mx + b form) to direct the rest of the line. Our slope is -2, so every time x increases by one (move one notch to the right), your y value will be two units less than the previous y value.