Answer: Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
x-2*y-(-21)=0 Solve x-2y+21 = 0
we recognizes that we have here an equation of a straight line. Such an equation is usually written y=mx+b ("y=mx+c" in the UK).
"y=mx+b" is the formula of a straight line drawn on Cartesian coordinate system in which "y" is the vertical axis and "x" the horizontal axis.
In this formula :
y tells us how far up the line goes
x tells us how far along
m is the Slope or Gradient i.e. how steep the line is
b is the Y-intercept i.e. where the line crosses the Y axis
The X and Y intercepts and the Slope are called the line properties. We shall now graph the line x-2y+21 = 0 and calculate its properties
Notice that when x = 0 the value of y is 21/2 so this line "cuts" the y axis at y=10.50000
y-intercept = 21/2 = 10.50000
Calculate the X-Intercept :
When y = 0 the value of x is -21/1 Our line therefore "cuts" the x axis at x=-21.00000
x-intercept = -21/1 = -21.00000
Calculate the Slope :
Slope is defined as the change in y divided by the change in x. We note that for x=0, the value of y is 10.500 and for x=2.000, the value of y is 11.500. So, for a change of 2.000 in x (The change in x is sometimes referred to as "RUN") we get a change of 11.500 - 10.500 = 1.000 in y. (The change in y is sometimes referred to as "RISE" and the Slope is m = RISE / RUN)
Slope = 1.000/2.000 = 0.500
Geometric figure: Straight Line
Slope = 1.000/2.000 = 0.500
x-intercept = -21/1 = -21.00000
y-intercept = 21/2 = 10.50000
I hope this helps have a great day!