已知代数式(4x²+ax-y+6)-(2bx²-2x+5y-1)的值于字母x的取值无关.求代数式 3(a²-2ab-b²)-(4a²+ab+b²)的值求各位亲们、好汉帮帮忙、行行好!
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![已知代数式(4x²+ax-y+6)-(2bx²-2x+5y-1)的值于字母x的取值无关.求代数式 3(a²-2ab-b²)-(4a²+ab+b²)的值求各位亲们、好汉帮帮忙、行行好!](/uploads/image/z/2112089-41-9.jpg?t=%E5%B7%B2%E7%9F%A5%E4%BB%A3%E6%95%B0%E5%BC%8F%EF%BC%884x%26%23178%3B%2Bax-y%2B6%29-%282bx%26%23178%3B-2x%2B5y-1%29%E7%9A%84%E5%80%BC%E4%BA%8E%E5%AD%97%E6%AF%8Dx%E7%9A%84%E5%8F%96%E5%80%BC%E6%97%A0%E5%85%B3.%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8F+3%28a%26%23178%3B-2ab-b%26%23178%3B%29-%284a%26%23178%3B%2Bab%2Bb%26%23178%3B%29%E7%9A%84%E5%80%BC%E6%B1%82%E5%90%84%E4%BD%8D%E4%BA%B2%E4%BB%AC%E3%80%81%E5%A5%BD%E6%B1%89%E5%B8%AE%E5%B8%AE%E5%BF%99%E3%80%81%E8%A1%8C%E8%A1%8C%E5%A5%BD%21)
已知代数式(4x²+ax-y+6)-(2bx²-2x+5y-1)的值于字母x的取值无关.求代数式 3(a²-2ab-b²)-(4a²+ab+b²)的值求各位亲们、好汉帮帮忙、行行好!
已知代数式(4x²+ax-y+6)-(2bx²-2x+5y-1)的值于字母x的取值无关.
求代数式 3(a²-2ab-b²)-(4a²+ab+b²)的值
求各位亲们、好汉帮帮忙、行行好!
已知代数式(4x²+ax-y+6)-(2bx²-2x+5y-1)的值于字母x的取值无关.求代数式 3(a²-2ab-b²)-(4a²+ab+b²)的值求各位亲们、好汉帮帮忙、行行好!
(4x²+ax-y+6)-(2bx²-2x+5y-1)=(4-2b)x²+(a+2)x-6y+7的字母取值与x无关
所以有4-2b=0,a+2=0,得a=-2,b=2
故3(a²-2ab-b²)-(4a²+ab+b²)=-7a²-7ab-4b²=-7*4+28-16=-16