.先化简再求值】x^4-y^4分之x²+y²分之1.先化简再求值】(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,其中x=-3分之1
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![.先化简再求值】x^4-y^4分之x²+y²分之1.先化简再求值】(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,其中x=-3分之1](/uploads/image/z/568339-43-9.jpg?t=.%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BC%E3%80%91x%5E4-y%5E4%E5%88%86%E4%B9%8Bx%26%23178%3B%2By%26%23178%3B%E5%88%86%E4%B9%8B1.%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BC%E3%80%91%EF%BC%881%EF%BC%89x%5E4-y%5E4%E5%88%86%E4%B9%8Bx%2By%C3%B7x%26%23178%3B%2By%26%23178%3B%E5%88%86%E4%B9%8B1%2C%E5%85%B6%E4%B8%ADx%3D8%2Cy%3D11%EF%BC%882%EF%BC%89x%26%23178%3B%2B6x%2B9%E5%88%86%E4%B9%8Bx%26%23178%3B-9%C3%97x%26%23178%3B-3x%E5%88%86%E4%B9%8B3x%26%23179%3B%2B9x%26%23178%3B%2C%E5%85%B6%E4%B8%ADx%3D-3%E5%88%86%E4%B9%8B1)
.先化简再求值】x^4-y^4分之x²+y²分之1.先化简再求值】(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,其中x=-3分之1
.先化简再求值】x^4-y^4分之x²+y²分之1
.先化简再求值】
(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11
(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,其中x=-3分之1
.先化简再求值】x^4-y^4分之x²+y²分之1.先化简再求值】(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,其中x=-3分之1
(x+y)/[1/(x^2+y^2)] /(x^4-y^4)
=(x+y)(x^2+y^2)/[(x^2-y^2)(x^2+y^2)]
=(x+y)/(x^2-y^2)
=1/(x-y)
=1/(8-11)
=-1/3
2) 先把括号打上,否则很难明白意思
(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11
原式=(x+y)/(x²+y²)(x+y)(x-y)×(x²+y²)
=1/(x-y)
当x=8,y=11时
原式=1/(8-11)=-1/3
(2)x²+6x+9分之x²-9×x²-3x分之3x&...
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(1)x^4-y^4分之x+y÷x²+y²分之1,其中x=8,y=11
原式=(x+y)/(x²+y²)(x+y)(x-y)×(x²+y²)
=1/(x-y)
当x=8,y=11时
原式=1/(8-11)=-1/3
(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,其中x=-3分之1
原式=(x+3)(x-3)/(x+3)²×3x²(x+3)/x(x-3)
=3x
当x=-1/3时
原式=3x=-1
收起
(1)(x^4-y^4)分之(x+y)÷(x²+y²)分之1
=(x²+y²)(x+y)(x-y)分之(x+y)乘以(x²+y²)
=(x-y)分之1
=3分之-1
(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,
=(x+3)...
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(1)(x^4-y^4)分之(x+y)÷(x²+y²)分之1
=(x²+y²)(x+y)(x-y)分之(x+y)乘以(x²+y²)
=(x-y)分之1
=3分之-1
(2)x²+6x+9分之x²-9×x²-3x分之3x³+9x²,
=(x+3)²分之(x-3)(x+3)乘以x(x-3)分之3(x+3)x²
=(x+3)²x(x-3)分之3(x-3)(x+3)(x+3)x²
=3x
=-1
收起