Find all values of $x$ which do not satisfy $$1 \le 4-3x+5x < 10-8x.$$ Express your answer in interval notation.
Simplify as
1 ≤ 4 + 2x < 10 - 8x
Splitting the inequalities, the x's that make this true are
1 ≤ 4 + 2x 4 + 2x < 10 - 8x
-3 ≤ 2x 10x < 6
-3/2 ≤ x x < 6/10
x < 3/5
So the intervals that DO NOT make this true are
(-inf, -3/2) U [3/5 , inf)
+1347 
