若3x²-x=1求6x³+7x²-5x+1994的值
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![若3x²-x=1求6x³+7x²-5x+1994的值](/uploads/image/z/224448-24-8.jpg?t=%E8%8B%A53x%26%23178%3B-x%3D1%E6%B1%826x%26%23179%3B%2B7x%26%23178%3B-5x%2B1994%E7%9A%84%E5%80%BC)
若3x²-x=1求6x³+7x²-5x+1994的值
若3x²-x=1求6x³+7x²-5x+1994的值
若3x²-x=1求6x³+7x²-5x+1994的值
6x³+7x²-5x+1994
=6x³-2x²-9x²-5x+1994
=2x(x²-x)-9x²-5x+1994
=2x-9x²-5x+1994
=-9x²-3x+1994
=-3(3x²-x)+1994
=-3x1+1994
=1994-3
=1991