三道化简求值题,2(-x²+5+4x)+(5x-4+2x²)其中x=-25(3a²b+ab²)-4(ab²+3a²b)其中a=2分之1,b=3分之1已知多项式A=3a²-6ab+b² B=-2a²+3ab-5b² 求2A-B+1
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![三道化简求值题,2(-x²+5+4x)+(5x-4+2x²)其中x=-25(3a²b+ab²)-4(ab²+3a²b)其中a=2分之1,b=3分之1已知多项式A=3a²-6ab+b² B=-2a²+3ab-5b² 求2A-B+1](/uploads/image/z/637741-37-1.jpg?t=%E4%B8%89%E9%81%93%E5%8C%96%E7%AE%80%E6%B1%82%E5%80%BC%E9%A2%98%2C2%EF%BC%88-x%26%23178%3B%2B5%2B4x%EF%BC%89%2B%EF%BC%885x-4%2B2x%26%23178%3B%EF%BC%89%E5%85%B6%E4%B8%ADx%3D-25%EF%BC%883a%26%23178%3Bb%2Bab%26%23178%3B%EF%BC%89-4%EF%BC%88ab%26%23178%3B%2B3a%26%23178%3Bb%EF%BC%89%E5%85%B6%E4%B8%ADa%3D2%E5%88%86%E4%B9%8B1%2Cb%3D3%E5%88%86%E4%B9%8B1%E5%B7%B2%E7%9F%A5%E5%A4%9A%E9%A1%B9%E5%BC%8FA%3D3a%26%23178%3B-6ab%2Bb%26%23178%3B+B%3D-2a%26%23178%3B%2B3ab-5b%26%23178%3B+%E6%B1%822A-B%2B1)
三道化简求值题,2(-x²+5+4x)+(5x-4+2x²)其中x=-25(3a²b+ab²)-4(ab²+3a²b)其中a=2分之1,b=3分之1已知多项式A=3a²-6ab+b² B=-2a²+3ab-5b² 求2A-B+1
三道化简求值题,
2(-x²+5+4x)+(5x-4+2x²)其中x=-2
5(3a²b+ab²)-4(ab²+3a²b)其中a=2分之1,b=3分之1
已知多项式A=3a²-6ab+b² B=-2a²+3ab-5b² 求2A-B+1
三道化简求值题,2(-x²+5+4x)+(5x-4+2x²)其中x=-25(3a²b+ab²)-4(ab²+3a²b)其中a=2分之1,b=3分之1已知多项式A=3a²-6ab+b² B=-2a²+3ab-5b² 求2A-B+1
2(-x²+5+4x)+(5x-4+2x²)
=-2x²+10+8x+5x-4+2x²
=13x+6
当x=-2时,原式=13*(-2)+6=-20
5(3a²b+ab²)-4(ab²+3a²b)
=15a²b+5ab²-4ab²-12a²b
=3a²b+ab²
当a=2分之1,b=3分之1时,原式=3*(1/2)²*1/3+1/2*(1/3)²=1/4+1/18=11/36
已知多项式A=3a²-6ab+b² B=-2a²+3ab-5b² 求
2A-B+1
=2(3a²-6ab+b² )-(-2a²+3ab-5b² )
=6a²-12ab+2b² +2a²-3ab+5b²+1
=8a²-15ab+7b²+1
=-2x^2+10+8x+5x-4+2x^2=13x+6=26+6=32 =15a^2b+5ab^2-4ab^2-12a^2b=3a^2b+ab^2=1/4+1/18=11/36 2A-B+1=6a^2-12ab+2b^2+2a^2-3ab+5b^2+1=8a^2-15ab+7b^2+1