Answer: see below
Explanation:
17) 5n - 3 > -2n + 4 and 9 - 4n ≥ -2n + 1
+2n +2n +2n +2n
7n - 3 > 4 9 - 2n ≥ 1
+3 +3 -9 -9
7n > 7 -2n ≥ -8
÷7 ÷7 ÷ -2 ↓ ÷ -2
n > 1 and n ≤ 4
Graph: o----------------- ·
1 4
18) 9k - 2 ≤ 9 + 10k < 9 - 4k
9k - 2 ≤ 9 + 10k and 9 + 10k < 9 - 4k
-10k -10k +4k +4k
-k - 2 ≤ 9 9 + 14k < 9
+2 +2 -9 -9
-k ≤ 11 14k < 0
÷ -1 ↓ ÷ -1 ÷14 ÷14
k ≥ -11 and k < 0
Graph: · -----------------o
-11 0
19) 4 - n ≤ 10 + 5n ≤ 6n + 1
4 - n ≤ 10 + 5n and 10 + 5n ≤ 6n + 1
-5n -5n -6n -6n
4 - 6n ≤ 10 10 - n ≤ 1
-4 -4 -10 -10
-6n ≤ 6 -n ≤ -9
÷ -6 ↓ ÷ -6 ÷ -1 ↓ ÷ -1
n ≥ -1 and n ≥ 9
Graph: · -----------------→
-9
20) 4p - 5 ≤ 2p + 9 ≤ 4p + 7
4p - 5 ≤ 2p + 9 and 2p + 9 ≤ 4p + 7
-2p -2p -4p -4p
2p - 5 ≤ 9 -2p + 9 ≤ 7
+5 +5 -9 -9
2p ≤ 14 -2p ≤ -2
÷ 2 ÷ 2 ÷ -2 ↓ ÷ -2
p ≤ 7 and p ≥ 1
Graph: · ----------------- ·
1 7