85
2007-02-20 14:00:54
0
1번.
multiply (x-2) to both sides,
-3x - 4 ≥ (x+2)(x-2) becomes
-3x - 4 ≥ x^2 - 4
add 3x + 4 to both sides to move ones on the left to the right.
0 ≥ x^2 + 3x becomes
0 ≥ x(x + 3)
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-3 0
2번
-4 ≤ x-6 ≤ 4
add 6 to all three sides,
2 ≤ x ≤ 10
수고하세요.