若二次多项式a²+2a+m中以2代替a,则代数式的值为0,求m的值已知|a-½|+(b+2)²=0,求代数式a³-3a²b+4ab²-2b³的值.已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.
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![若二次多项式a²+2a+m中以2代替a,则代数式的值为0,求m的值已知|a-½|+(b+2)²=0,求代数式a³-3a²b+4ab²-2b³的值.已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.](/uploads/image/z/1586720-56-0.jpg?t=%E8%8B%A5%E4%BA%8C%E6%AC%A1%E5%A4%9A%E9%A1%B9%E5%BC%8Fa%26%23178%3B%2B2a%2Bm%E4%B8%AD%E4%BB%A52%E4%BB%A3%E6%9B%BFa%2C%E5%88%99%E4%BB%A3%E6%95%B0%E5%BC%8F%E7%9A%84%E5%80%BC%E4%B8%BA0%2C%E6%B1%82m%E7%9A%84%E5%80%BC%E5%B7%B2%E7%9F%A5%7Ca-%26%23189%3B%7C%2B%28b%2B2%29%26%23178%3B%3D0%2C%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8Fa%26%23179%3B-3a%26%23178%3Bb%2B4ab%26%23178%3B-2b%26%23179%3B%E7%9A%84%E5%80%BC.%E5%B7%B2%E7%9F%A5x%2By%3D3%2C%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8F3%EF%BC%88x%2By%EF%BC%89%26%23178%3B-4%2Fx%2By%2B2x-3%2B2y%E7%9A%84%E5%80%BC.)
若二次多项式a²+2a+m中以2代替a,则代数式的值为0,求m的值已知|a-½|+(b+2)²=0,求代数式a³-3a²b+4ab²-2b³的值.已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.
若二次多项式a²+2a+m中以2代替a,则代数式的值为0,求m的值
已知|a-½|+(b+2)²=0,求代数式a³-3a²b+4ab²-2b³的值.
已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.
若二次多项式a²+2a+m中以2代替a,则代数式的值为0,求m的值已知|a-½|+(b+2)²=0,求代数式a³-3a²b+4ab²-2b³的值.已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.
已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.
3(x+y)²-4/x+y+2x-3+2y
=3(x+y)²-4/(x+y)+2(x+y)-3
=27-4/3+6-3
=30-4/3
=28又 2/3
若二次多项式a²+2a+m中以2代替a,则代数式的值为0,求m的值
2²+2*2+m=0
m=-8
已知|a-½|+(b+2)²=0,求代数式a³-3a²b+4ab²-2b³的值.
a-1/2=0
b+2=0
∴a=1/2,b=-2
a³-3a²b+4ab²-2b³
=1/8+3/2-8+16
=9又5/8
已知x+y=3,求代数式3(x+y)²-4/x+y+2x-3+2y的值.
见上
1.m=-8
2.a=1/2,b=-2,代入
原式=25.625
3.代入即可
=3*9-4/3+2*3-3
=86/3
请采纳!
1、m为-4
2、27又1/8
3、31又 1/3