Given:
The gradient of the line passing through A(2,3), B(k,7) is [tex]\dfrac{2}{3}[/tex].
To find:
The value of k.
Solution:
The gradient or slope of a line is:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
The gradient of the line passing through A(2,3), B(k,7) is [tex]\dfrac{2}{3}[/tex]. So,
[tex]\dfrac{2}{3}=\dfrac{7-3}{k-2}[/tex]
[tex]\dfrac{2}{3}=\dfrac{4}{k-2}[/tex]
On cross multiplication, we get
[tex]2(k-2)=4(3)[/tex]
[tex]2k-4=12[/tex]
[tex]2k=12+4[/tex]
[tex]2k=16[/tex]
Divide both sides by 2.
[tex]k=\dfrac{16}{2}[/tex]
[tex]k=8[/tex]
Therefore, the value of k is 8.