Question

17*11*2+17*11*5 is a composite number

Answer 1

(17*11*2)+(17*11*5 )
 374 + 935
  =1309

its a composite no. as it has more than 3 factors (1,1309,7,187...)

Answer 2

17*11*2+17*11*5= 17*11(2+5)
                              = 17*11*7
                              = 1309
Yes, it is composite number because it has factors   17, 11, 7, 1, 1309
(more than two factors)