用乘法公式进行计算!1.(x-y)(-x-y)(x²+y²)2.5(3-5a)²-5(3a-7)(3a+7)
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用乘法公式进行计算!1.(x-y)(-x-y)(x²+y²)2.5(3-5a)²-5(3a-7)(3a+7)
用乘法公式进行计算!
1.(x-y)(-x-y)(x²+y²)
2.5(3-5a)²-5(3a-7)(3a+7)
用乘法公式进行计算!1.(x-y)(-x-y)(x²+y²)2.5(3-5a)²-5(3a-7)(3a+7)
1.(x-y)(-x-y)(x²+y²)
= - (x-y)(x+y)((x²+y²)
= - (x²-y²)(x²+y²)
= - x的四次方+y的四次方
楼上的计算错误了,纠正下
2.5(3-5a)²-5(3a-7)(3a+7)
=5(3-5a)²-5(9a²-49)
=5[(9-30a+25a²)- (9a²-49)]
=5[9-30a+25a²- 9a²+49]
=5(16a²-30a+58)
=80a²-150a+290
1=-(x-y)(x+y)(x²+y²)=-(x²-y²)(x²+y²)=y4-x4
2=5(25a2-30a+9)-5(9a2-49)=5(16a2-30a-40)=58a2-150a-200
1.(x-y)(-x-y)(x²+y²)=-(x-y)(x+y)(x²+y²)=-(x²-y²)(x²+y²)=-(x^4-Y^4)=-X^4-Y^4
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(x-y)(-x-y)(x²-y2) 5(3-5a)²-5(3a-7)(3a+7)
=(y2-x²)(x²+y2) =5【(3-5a)²-(3a-7)²】
=y4-x4 =-16a²-52a-40