EXPLANATION
Given the ordered pairs: (1,9) and (-3,-9)
Slope-intercept form definition is:
y=mx+ b
is the slope-intercept form of a line where m is the slope and b is the y-intercept.
Compute the slope (1,9) and (-3,-9):
Slope between two points:
[tex]\text{Slope = }\frac{(y2-y1)}{(x2-x1)}[/tex](x1,y1) = (1,9) (x2,y2) = (-3,-9)
[tex]m=\frac{(-9-9)}{(-3-1)}=\text{ }\frac{9}{2}[/tex]Compute the y-intercept:
Plug the slope 9/2 into y= mx +b
y=9/2x + b
Plug in (1,9):
9= 9/2*1 + b
Switch sides:
9/2 + b = 9
Subtract 9/2 from both sides:
9/2 + b -9/2 = 9 -9/2
Simplify:
b = 9/2
Construct the line equation y=mx+b where m=9/2 and b=9/2
y= 9/2x + 9/2
A
