This expression tree is for scientific mode for the problem 3*4+6/2+2*5 is:

To do the problem with an expression tree you need to collapse the nodes (numbers) with there operators (such as *,+,and/).

This is how it looks after you've done the first collapsing. You see that the 3,4,and * are gone? That's because the way you collapse is do the numbers against there operator so that you come out with the answer .

This is what you get after you do the 2nd collapsing. This time do you see the difference? Yep the /,6, and 2 are gone because I did the same thing except I divided them instead of multiplying them.

This is what you get after the 3rd collapsing and its easy to spot the difference right? Well if you can't the 12,3,and the + are gone and there is a 15. That's because there was a + above the 12 and the 3 so I added them together.

This is what it looks like after the 4th collapsing. The difference here is very easy to spot. The 2,5,and 2nd * are gone and instead there is a 10. That's because the * was above the 2 and 5 so I multiplied them together.

This is the easiest difference to spot of all. The 10 and 15 and the + are gone and there instead there is a 25.That's because the + was above the 10 and 15 so I added them together.

Here is the assembly program to evaluate the above expression tree:

; 3 * 4 + 6 / 2 + 2 * 5

mov eax,3

mov ebx,4

mul ebx ; This collapses 3 * 4 to 12 into eax

mov ecx,eax ; This moves eax into ecx temporarily

mov eax,6

mov ebx,2

div ebx ; This collapses 6 / 2 to 3 into eax

add ecx,eax ; This collapses 3 * 4 and 6 / 2 together into 15

mov eax,2

mov ebx,5

mul ebx ; This collapses 2 * 5 to 10 into eax

add eax,ecx ; This collapses 15 and 10 into 25