Question 17645
Hi, hope I'm understanding the question correctly.  Looks like an order of operations situation to me.  

Remembering that multiplication is to be performed first (in order from left to right), the problem could be rewritten as such:  (7*13)+(8*13)+(5*13). 

Working out each set of parentheses, you would then have (91) + (104) + (65).  Adding the three together your answer would be 260.