Is this correct? I really need to know this

Answer:
Slope (m) = 2
Step-by-step explanation:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
consider 2 points - (20,20) and (30,40)
[tex]m = \frac{40-20}{30-20}[/tex]
[tex]m=\frac{20}{10}[/tex]
[tex]m=2\\[/tex]
∴ Slope (m) = 2