# Double sum

1. Apr 1, 2008

### sapiental

1. The problem statement, all variables and given/known data

Compute the following double sum

(n=3)(i=0)$$\sum$$(n=2)(j=0)$$\sum$$(3i+2j)

2. Relevant equations

sums

3. The attempt at a solution

my answer follows expanding the first sum, then just doing the last one

i get

(n=3)(i=0)$$\sum[tex](6+9i) = 78 thanks! 2. Apr 1, 2008 ### sutupidmath [tex]\sum_{i=0}^{n=3} \sum_{j=0}^{n=2}(3i+2j)=\sum_{i=0}^{n=3}(6+9i)=78$$

Looks good to me.