十分钟回答另加30分!已知:a²-ab=15,ab-b²=12 求:a²-2ab+b²1.:a²-ab=15,ab-b²=12 求:a²-2ab+b²2.大客车上原有(3a-b)人,中途一半人下车,又上车若干人使车上共有乘客(8a-5b)人,问
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![十分钟回答另加30分!已知:a²-ab=15,ab-b²=12 求:a²-2ab+b²1.:a²-ab=15,ab-b²=12 求:a²-2ab+b²2.大客车上原有(3a-b)人,中途一半人下车,又上车若干人使车上共有乘客(8a-5b)人,问](/uploads/image/z/5155039-55-9.jpg?t=%E5%8D%81%E5%88%86%E9%92%9F%E5%9B%9E%E7%AD%94%E5%8F%A6%E5%8A%A030%E5%88%86%21%E5%B7%B2%E7%9F%A5%3Aa%26sup2%3B-ab%3D15%2Cab-b%26sup2%3B%3D12+%E6%B1%82%3Aa%26sup2%3B-2ab%2Bb%26sup2%3B1.%3Aa%26sup2%3B-ab%3D15%2Cab-b%26sup2%3B%3D12+%E6%B1%82%3Aa%26sup2%3B-2ab%2Bb%26sup2%3B2.%E5%A4%A7%E5%AE%A2%E8%BD%A6%E4%B8%8A%E5%8E%9F%E6%9C%89%EF%BC%883a-b%29%E4%BA%BA%2C%E4%B8%AD%E9%80%94%E4%B8%80%E5%8D%8A%E4%BA%BA%E4%B8%8B%E8%BD%A6%2C%E5%8F%88%E4%B8%8A%E8%BD%A6%E8%8B%A5%E5%B9%B2%E4%BA%BA%E4%BD%BF%E8%BD%A6%E4%B8%8A%E5%85%B1%E6%9C%89%E4%B9%98%E5%AE%A2%EF%BC%888a-5b%29%E4%BA%BA%2C%E9%97%AE)
十分钟回答另加30分!已知:a²-ab=15,ab-b²=12 求:a²-2ab+b²1.:a²-ab=15,ab-b²=12 求:a²-2ab+b²2.大客车上原有(3a-b)人,中途一半人下车,又上车若干人使车上共有乘客(8a-5b)人,问
十分钟回答另加30分!已知:a²-ab=15,ab-b²=12 求:a²-2ab+b²
1.:a²-ab=15,ab-b²=12 求:a²-2ab+b²
2.大客车上原有(3a-b)人,中途一半人下车,又上车若干人使车上共有乘客(8a-5b)人,问中间上车乘客多少人?
3.若多项式2mx²-x²+5x+8-(7x²-3y+5x)的值与x无关,求:m²-[2m²-(5m-4)+m]的值.
十分钟回答另加30分!已知:a²-ab=15,ab-b²=12 求:a²-2ab+b²1.:a²-ab=15,ab-b²=12 求:a²-2ab+b²2.大客车上原有(3a-b)人,中途一半人下车,又上车若干人使车上共有乘客(8a-5b)人,问
1
a²-2ab+b²=a²-ab-(ab-b²)
=15-12=3
2
中途一半人下车 变为(3a-b)/2人
上车乘客人数
=(8a-5b)-(3a-b)/2
=13/2a-9/2b
3
2mx²-x²+5x+8-(7x²-3y+5x)的值与x无关
化解(2m-8)x²+3y+8
所以m=4
m²-[2m²-(5m-4)+m]
=-m²+(5m-4)-m
=-m²+4m-4
=-(m-2)²
=-4
1、a²-ab=15,ab-b²=12
两式相减得a²-2ab+b²=3
2、8a-5b-(3a-b)/2=13a/2-9b/2
3、多项式2mx²-x²+5x+8-(7x²-3y+5x)的值与x无关
∴2m-1-7=0
m=4
m²-[2m²-(5m-4)+m]
=m²-2m²+(5m-4)-m
=-m²+4m-4
=-(m-2)²
=-4
1.a²-2ab+b²=(a²-ab)-(ab-b²)=15-12=3
2.3a-b-(3a-b)/2+x=8a-5b x=(13/2)a-(9/2)b
第三个不会了
1.a²-2ab+b²=a²-ab-(ab-b²)=15-12=3
2.(8a-5b)-(3a-b)/2
3.解:(2mx^2-x^2+5x+8)-(7x^2-3y+5x)
=2mx^2-x^2+5x+8-7x^2+3y-5x
=(2mx^2-x^2-7x^2)+3y+8
=(2m-8)x^2++3y+8因为值与x无关...
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1.a²-2ab+b²=a²-ab-(ab-b²)=15-12=3
2.(8a-5b)-(3a-b)/2
3.解:(2mx^2-x^2+5x+8)-(7x^2-3y+5x)
=2mx^2-x^2+5x+8-7x^2+3y-5x
=(2mx^2-x^2-7x^2)+3y+8
=(2m-8)x^2++3y+8因为值与x无关,所以含x的项就不存在,所以2m-8=0
所以m=4
m²-[2m²-(5m-4)+m]=4²-2*4²+5*4-4-4=-4
收起
1.等于3
2.(13a-9b)/2
3.-4