(4 - x ≤ -1) ∩ (2 + 3x ≥ 17). (-x ≤ -5) ∩ (3x ≥ 15). The inequality reverses in the left part since we are dividing through by a negative number -1. (x ≥ 5) ∩ (x ≥ 5). Draw each part on a number line -------------------------------@===========> That's x ≥ 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 -------------------------------@===========> That's x ≥ 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 Intersection ∩ means to use ONLY the part where the two graphs overlap, that is, the part of the number line where BOTH are true and darkened or shaded ===. @ means a darkened circle. But they (overlap) intersect EVERYWHERE!!! -------------------------------@===========> -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 So that is x ≥ 5, which in scientific notation is [5,oo) where oo indicates "infinity". Edwin
(4 - x ≤ -1) ∩ (2 + 3x ≥ 17). (-x ≤ -5) ∩ (3x ≥ 15). The inequality reverses in the left part since we are dividing through by a negative number -1. (x ≥ 5) ∩ (x ≥ 5). Draw each part on a number line -------------------------------@===========> That's x ≥ 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 -------------------------------@===========> That's x ≥ 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 Intersection ∩ means to use ONLY the part where the two graphs overlap, that is, the part of the number line where BOTH are true and darkened or shaded ===. @ means a darkened circle. But they (overlap) intersect EVERYWHERE!!! -------------------------------@===========> -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 So that is x ≥ 5, which in scientific notation is [5,oo) where oo indicates "infinity". Edwin