求下列各式的值⒈ (3x^4-2x^3)÷(-x)-(x-x^2)·3x,其中x=-1/2⒉ [(ab+1)(ab-2)-2a^2b^2+2]÷(-ab),其中a=3/2,b=-4/3已知(x+y)^2=1,(x-y)^2=49,求x^2+y^2与xy的值已知a=b=3,ab=2,求a6^2=b6^2
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![求下列各式的值⒈ (3x^4-2x^3)÷(-x)-(x-x^2)·3x,其中x=-1/2⒉ [(ab+1)(ab-2)-2a^2b^2+2]÷(-ab),其中a=3/2,b=-4/3已知(x+y)^2=1,(x-y)^2=49,求x^2+y^2与xy的值已知a=b=3,ab=2,求a6^2=b6^2](/uploads/image/z/2110005-45-5.jpg?t=%E6%B1%82%E4%B8%8B%E5%88%97%E5%90%84%E5%BC%8F%E7%9A%84%E5%80%BC%E2%92%88+%283x%5E4-2x%5E3%29%C3%B7%28-x%29-%28x-x%5E2%29%C2%B73x%2C%E5%85%B6%E4%B8%ADx%3D-1%2F2%E2%92%89+%5B%28ab%2B1%29%28ab-2%29-2a%5E2b%5E2%2B2%5D%C3%B7%28-ab%29%2C%E5%85%B6%E4%B8%ADa%3D3%2F2%2Cb%3D-4%2F3%E5%B7%B2%E7%9F%A5%28x%2By%29%5E2%3D1%2C%28x-y%29%5E2%3D49%2C%E6%B1%82x%5E2%2By%5E2%E4%B8%8Exy%E7%9A%84%E5%80%BC%E5%B7%B2%E7%9F%A5a%3Db%3D3%2Cab%3D2%2C%E6%B1%82a6%5E2%3Db6%5E2)
求下列各式的值⒈ (3x^4-2x^3)÷(-x)-(x-x^2)·3x,其中x=-1/2⒉ [(ab+1)(ab-2)-2a^2b^2+2]÷(-ab),其中a=3/2,b=-4/3已知(x+y)^2=1,(x-y)^2=49,求x^2+y^2与xy的值已知a=b=3,ab=2,求a6^2=b6^2
求下列各式的值
⒈ (3x^4-2x^3)÷(-x)-(x-x^2)·3x,其中x=-1/2
⒉ [(ab+1)(ab-2)-2a^2b^2+2]÷(-ab),其中a=3/2,b=-4/3
已知(x+y)^2=1,(x-y)^2=49,求x^2+y^2与xy的值
已知a=b=3,ab=2,求a6^2=b6^2
求下列各式的值⒈ (3x^4-2x^3)÷(-x)-(x-x^2)·3x,其中x=-1/2⒉ [(ab+1)(ab-2)-2a^2b^2+2]÷(-ab),其中a=3/2,b=-4/3已知(x+y)^2=1,(x-y)^2=49,求x^2+y^2与xy的值已知a=b=3,ab=2,求a6^2=b6^2
求下列各式的值
⒈ (3x^4-2x^3)÷(-x)-(x-x^2)·3x,其中x=-1/2
=(-3x^3+2x^2)-(3x^2-3x^3)
=5x^2
=5*(-1/2)^2
=5/4
⒉ [(ab+1)(ab-2)-2a^2b^2+2]÷(-ab),其中a=3/2,b=-4/3
=(a^2b^2-ab-2-2a^2b^2+2)/(-ab)
=(a^2b^2+ab)/(ab)
=ab+1
=3/2*(-4/3)+1
=-2+1
=-1
已知(x+y)^2=1,(x-y)^2=49,求x^2+y^2与xy的值
(x+y)^2=x^2+2xy+y^2=1
(x-y)^2=x^2-2xy+y^2=49
x^2+y^2=(1+49)/2=25
xy=(1-49)/4=-12
已知a=b=3,ab=2,求a6^2=b6^2
a6^2什么意思?
是不是这样的:
a+b=3,ab=2
a^2+b^2=(a+b)^2-2ab=3^2-2*2=5