odd integers are 2 apart
the 3 consecutive odd numbers are x,x+2, x+4
sum is x+x+2+x+4 or 3x+6
the sum is 15 more than 2 times middle one
3x+6=15+2(x+2)
3x+6=15+2x+4
3x+6=19+2x
minus 2x both side
x+6=19
minus 6 both sides
x=13
x+2=15
x+4=17
they are 13,15,17
