The value of missing coordinate "r" is -4
Solution:
Given that,
The points (1, r) and (4, -13) lie on a line with slope – 3
To find: missing coordinate r
The slope of a line is given by formula:
[tex]m = \frac{y_2-y_1}{x_2-x_1}[/tex]
Where, "m" is the slope of line
Here in this sum,
m = -3
[tex](x_1, y_1) = (1, r)\\\\(x_2, y_2) = (4, -13)[/tex]
Substituting the values in formula,
[tex]-3 = \frac{-13-r}{4-1}\\\\-3=\frac{-13-r}{3}\\\\-9 = -13 - r\\\\r = -13+9\\\\r = -4[/tex]
Thus the value of missing coordinate "r" is -4
