2(x?3)?2(x+3)+2x+18 |
(x+3)(x?3) |
2(x+3) |
(x+3)(x?3) |
2 |
x?3 |
當(dāng)x-3=2,即x=5時,原式值為整數(shù);
當(dāng)x-3=1,即x=4時,原式值為整數(shù);
當(dāng)x-3=-1,即x=2時,原式值為整數(shù);
當(dāng)x-3=-2,即x=1時,原式值為整數(shù),
則符號條件的x有4個.
故選C
2 |
x+3 |
2 |
3?x |
2x+18 |
x2?9 |
2(x?3)?2(x+3)+2x+18 |
(x+3)(x?3) |
2(x+3) |
(x+3)(x?3) |
2 |
x?3 |