The first equation is

The second equation is

If you sum the two equations you'll cancel y:

And since the sum must be 11, we have y=9.
Answer:
In the equation y = mx + b for a straight line, the number m is called the slope of the line. Let x = 0, then y = m • 0 + b, so y = b. The number b is the coordinate on the y-axis where the graph crosses the y-axis.
Answer:
D, supplementary, BC, D
Step-by-step explanation: