初二上学期数学题(1)16m²n²-(m²+4n²)²(2)先化简,后求值:(a/a-b-a²/a²-2ab+b²)÷(a/a+b-a²/a²-b²)+1,其中a=2/3,b=-3急求..
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![初二上学期数学题(1)16m²n²-(m²+4n²)²(2)先化简,后求值:(a/a-b-a²/a²-2ab+b²)÷(a/a+b-a²/a²-b²)+1,其中a=2/3,b=-3急求..](/uploads/image/z/3844839-39-9.jpg?t=%E5%88%9D%E4%BA%8C%E4%B8%8A%E5%AD%A6%E6%9C%9F%E6%95%B0%E5%AD%A6%E9%A2%98%EF%BC%881%2916m%26%23178%3Bn%26%23178%3B%EF%BC%8D%EF%BC%88m%26%23178%3B%2B4n%26%23178%3B%EF%BC%89%26%23178%3B%EF%BC%882%EF%BC%89%E5%85%88%E5%8C%96%E7%AE%80%2C%E5%90%8E%E6%B1%82%E5%80%BC%EF%BC%9A%28a%2Fa%EF%BC%8Db%EF%BC%8Da%26%23178%3B%2Fa%26%23178%3B%EF%BC%8D2ab%2Bb%26%23178%3B%EF%BC%89%C3%B7%EF%BC%88a%2Fa%2Bb%EF%BC%8Da%26%23178%3B%2Fa%26%23178%3B%EF%BC%8Db%26%23178%3B%EF%BC%89%2B1%2C%E5%85%B6%E4%B8%ADa%3D2%2F3%2Cb%3D-3%E6%80%A5%E6%B1%82..)
初二上学期数学题(1)16m²n²-(m²+4n²)²(2)先化简,后求值:(a/a-b-a²/a²-2ab+b²)÷(a/a+b-a²/a²-b²)+1,其中a=2/3,b=-3急求..
初二上学期数学题
(1)16m²n²-(m²+4n²)²
(2)先化简,后求值:(a/a-b-a²/a²-2ab+b²)÷(a/a+b-a²/a²-b²)+1,其中a=2/3,b=-3
急求..
初二上学期数学题(1)16m²n²-(m²+4n²)²(2)先化简,后求值:(a/a-b-a²/a²-2ab+b²)÷(a/a+b-a²/a²-b²)+1,其中a=2/3,b=-3急求..
(1)16m²n²-(m²+4n²)²
=-[(m²+4n²)²-16m²n²]
=-(m²+4n²+4mn)(m²+4n²-4mn)
=-(m+2n)²(m-2n)²
(2)先化简,后求值:(a/a-b-a²/a²-2ab+b²)÷(a/a+b-a²/a²-b²)+1,其中a=2/3,b=-3
原式=[a/(a-b)-a²/(a-b)²]÷[a/(a+b)-a²/(a+b)(a-b)]+1
=[a(a-b)-a²]/(a-b)²÷[a(a-b)-a²]/(a+b)(a-b)+1
=(a+b)/(a-b)+1
=2a/(a-b)
当a=2/3 ,b=-3时
原式=(4/3)/(2/3+3)
=4/11