Given:
The slope of the line joining points (3,2) and (0,a) is -1.
To find:
The value of a.
Solution:
If a line passes through two points [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex], the slope of a line is:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
The slope of the line joining points (3,2) and (0,a) is -1. So,
[tex]\dfrac{a-2}{0-3}=-1[/tex]
[tex]\dfrac{a-2}{-3}=-1[/tex]
Multiply both sides by -3.
[tex]a-2=-1(-3)[/tex]
[tex]a-2=3[/tex]
[tex]a=3+2[/tex]
[tex]a=5[/tex]
Therefore, the value of a is 5.
