Answer:
[tex]4[/tex]Explanation:
Here, we want to get the greatest common factor between the two numbers
This means we want to get the highest number that is a factor of the two
We can start by factoring both numbers as follows;
[tex]\begin{gathered} 36\text{ = 2}\times2\times3\times3 \\ 40\text{ = 2}\times2\times2\times5 \end{gathered}[/tex]Looking at the factors, we can see that 2 * 2 is the highest we can take out as common to both numbers
That means the highest common factor of the two is 4