Thread: Homework help

Find the number of integer solutions of

1) x1 + x2 +x3 + x4= 15
x1 >1, x2 >0, x3 > 1, x4> 2


2) x1 + x2 + x3 + x4 =12
xi >0, i= 1,2,3,4.

Hello, Laura!

Here's the second one . . .the easier of the two.

Find the number of integer solutions of: .

Consider 12 objects in a row; leave a space between them.

. .

There are 11 spaces.
We choose 3 of them to insert "dividers."

So that: .

. . And: .


Therefore, there are: . solutions.