This is a hard problem for me. I have been stuck on it for days. I have a test coming up. Help me quick.

a multiple of 6 can be written as 6n, where n is any integer

three consecutive multiples of 6 would be 6n, 6(n+1), and 6(n+2)

-6<6n+6(n+1)+6(n+2)<50

-6<6n+6n+6+6n+12<50

-6<18n+18<50

-6-18<18n+18-18<50-18

-24<18n<32

-24/18<18n/18<32/18

-1 6/18<n<1 14/18

-1 1/3<n<1 7/9

n is an integer

therefore, n=-1, n=0, and n=1

if n=-1, then you have 6(-1), 6(-1+1), 6(-1+2), 6(-1), 6(0), 6(1), or -6, 0, 6

if n=0, then you have 6(0), 6(0+1), 6(0+2), 6(0), 6(1), 6(2), or 0, 6, 12

if n=1, then you have 6(1), 6(1+1), 6(1+2), 6(1), 6(2), 6(3), or 6, 12, 18

you can't have -12, -6, 0 because they add up to -18 which is less than -6

you can't have 12, 18, 24 because they add up to 54 which is greater than 50