We have these two equations
1 ≤ 4 - 3y and 4 - 3y < 10 rearrange both as
3y ≤ 4 - 1 -6 < 3y
3y ≤ 3 divide both sides by 3
y ≤ 1 -2 < y
So....the interval that solves this is (-2, 1 ]
So...the y's that DON'T solve this are
(-inf, -2] and (1, infinity )
