Question

求解 下列各题。运用完全平方公式的。请写出过程、答案。在线等呐~~~~

①﹙-3a-b﹚² ②﹙a+b﹚²-﹙a-b﹚² 用两种方法做 ③3﹙m+1﹚²-5﹙m+1﹚﹙m-1﹚+2﹙m-1﹚² ④﹙5x²-4y﹚﹙-5x²+4y﹚ ⑤﹙x-1﹚﹙x+1﹚﹙x²-1﹚ ⑥98² ⑦50.1² ⑧﹙x-3y﹚﹙x+3y﹚-﹙x-3y﹚² ⑨﹙2x-y-3﹚﹙2x+y+3﹚ ⑩﹙5x+7y﹚²-﹙5x-7y﹚²

Answer 1

1 、原式=（-3a)²+2（-3a)(-b)+(-b)²=9a²+6ab+b²
2、原式=（a^2+2ab+b^2)-(a^2-2ab+b^2)=4ab
原式=【（a+b)+(a-b)][(a+b)-(a-b)]=2a*2b=4ab
3、原式=3(m^2+2m+1)-5(m^2-1)+2(m^2-2m+1)=3m^2+6m+3-5m^2+5+2m^2-4m+2=2m+10
4、原式=-(5x^2-4y)^2=-(25x^4-40x^2y+16y^2)=-25x^4+40x^2y-16y^2
5、原式=(x^2-1)(x^2+1)=x^4-1
6、原式=(100-2)^2=10000-400+4=9604
7、原式=(50+0.1)^2=2500+10+0.01=2510.01
8、原式=(x^2-9y^2)-(x^2-6xy+9y^2)=x^2-9y^2-x^2+6xy-9y^2=6xy-18y^2
9、原式=【2x-(Y+3)][2x+(Y+3)]=4x^2-(y+3)^2=4x^2-(y^2+6y+9)=4x^2-y^2-6y-9
10、原式=(25x^2+70xy+49y^2)-(25x^2-70xy+49y^2)=25x^2+70xy+49y^2-25x^2+70xy-49y^2=140xy
原式=10x*14y=140xy

Answer 2

①﹙-3a-b﹚² =﹙3a+b﹚² =9a∧2+6ab+b∧2 ②﹙a+b﹚²-﹙a-b﹚² =[(a+b)-(a-b)][(a+b)+(a-b)]=2b×2a=4ab访法2：原式=（a∧2+2ab+b∧2）-（a∧2-2ab+b∧2）=2ab+2ab=4ab ③3﹙m+1﹚²-5﹙m+1﹚﹙m-1﹚+2﹙m-1﹚² =[3﹙m+1﹚-2﹙m-1﹚][﹙m+1﹚-﹙m-1﹚]=2(m+5) ④﹙5x²-4y﹚﹙-5x²+4y﹚=-﹙5x²-4y﹚﹙5x²-4y﹚=-25x∧4+40x²y-16y∧2 ⑤﹙x-1﹚﹙x+1﹚﹙x²-1﹚=(x²-1)(x²-1)=x∧4-2x∧2+1 ⑥98² =（100-2）²=10000-400+4=9604 ⑦50.1²=（50+0.1）²=2500+10+0.01=2510.01 ⑧﹙x-3y﹚﹙x+3y﹚-﹙x-3y﹚²=（x-3y）[(x+3y)-(x-3y)]=6y(x-3y)=6xy-18y² ⑨﹙2x-y-3﹚﹙2x+y+3﹚=[2x-(y+3﹚][﹙2x+(y+3﹚]=4x²-(y+3﹚²=4x²-y²-6y-9 ⑩﹙5x+7y﹚²-﹙5x-7y﹚²=[﹙5x+7y﹚-﹙5x-7y﹚][﹙5x+7y﹚+﹙5x-7y﹚]=14y×10x=140xy

Answer 3

1) =(3a+b)²
2) =a²+2ab+b²-(a²-2ab-b²)=4ab
=(a+b+a-b)(a+b-a+b)=2a*2b=4ab
3) =[3(m+1)-2(m-1)][m+1-(m-1)]=2(m+5)
4) =(5x²-4y)*[-(5x²-4y)]=-(5x²-4y)²
5) =(x²-1)(x²-1)=(x²-1)²
6) =(100-2)²=100²-2*2*100+2²=10000-400+4=9604
7) =(50+0.1)²=2500+10+0.01=2510.01
8) =x²-9y²-(x²-6xy+9y²)=6xy-18y²
9) =[2x-(y+3)]*[2x+(y+3)]=4x²-(y+3)²
10) =[5x+7y+5x-7y]*[5x+7y-(5x-7y)]=10x*14y=140xy

追问

要具体过程？？？