2a (x y)-2(a b)合并同类项-搜答案-神马作文网

-a-a=(-a(1+1))=(-2a);-3xy+3xy=(xy(-3+3))=(0);5n²-2n²+3n=(n²(5-2+3))=(6n²);-6ab+6

1.x-z/xy - 2ab/xy

1=(x-z-2ab)/xy2=(a²-2ab+b²)/a-b=(a-b)²/a-b=a-

5ab^2-7a^2b-8ab^2-3a^2b=-3ab^2-10a^2

a＝＿＿＿2＿,b＝＿＿-1/2＿＿＿xy和常数项系数分别为2b+a-1,a-2因为不含xy和常数项所以2b+a-1=0a-2=0解得：a=2,b=-1/2

原式=（1-1/5）xy^2=4/5xy^2原式=（-3+2）x^2y+(3-2)xy^2=-x^2y+xy^2原式=（4-4）a^2+(3-4)b^2+2ab-4=-b^2+2ab-4合并同类项,只

xy^2-1/5xy^24／5xy²-3x^2y+2x^2y+3xy^2-2xy^2-x²y+xy²4a^2+3b^2+2ab-4a^2-4b^22ab-b²2

去括号5c²-（a²-b²-ab）=5c²-a²+b²+ab-m+（-n+p-q)=-m-n+p-qxy-(-2x²-y²

：-a-a=（-2a）-3xy+3xy=（0）-3m²+10m²=（7m²）-5ab+2ab-ab=（-4ab）2y+3xy-5y=（3xy-3y）3a+2b-3b+5a

原式=2xy²+3xy²-6x²y+3xy²=8xy²-6x²y

-x^2y+5xy^2-yx^2=-2x^2y+5xy^2

题目是不是打错啦,如果没错就是4a^2b=16^b*a^2b3b^2=9b2ab-4ab^2-2ab=16*a^2*b^2再问：不少，这是基础训练上的题再答：我想问一下这是一道题还是3到题？再问：1道

7xy-8wx+5xy-12xy=(7xy+5xy-12xy)-8wxx=0-8wx=-8wx2a+3b+6a+9b-8a+12b=(2a+6a-8a)+(3b+9b+12b)=0+24b=24b30

（1）4X-5X=-x（2）-1/3AB的2次方+AB的2次方=2/3AB^2（3）4A-5A+8A=7A（4）-2X+3Y+7X-1/2Y=5x+5/2yX的2次方-2X的2次方+5-X的2次方-3

3a-2a^2+4-3a^2+a=（3+1）a+(-2-3)a²+4=4a-5a²+4xy+2xy-3x^2-3xy+x^2=(1+2-3)xy+(-3+1)x²=-2x

6a²-2ab-2(3a²-1/2ab)=6a²-2ab-6a²+ab=-a

a²-2ab+b²+2a²+2ab-b²=(a²+2a²)+(-2ab+2ab)+(b²-b²)=3a²

5aˇ2b-7abˇ2-8aˇ2b+9abˇ2=-3aˇ2b+2abˇ2

-5a^2b+6ab^2-4ab-2a^2b+4ab+3=-5a^2b-2a^2b+6ab^2-4ab+4ab+3=(-5-2)a^2b+6ab^2+3=-7a^2b+6ab^2+36x+2x^2-3

（1）6x＋2x－3x＋x＋1＝6x＋1其中x＝5原式＝30＋1＝31（2）1／3m-3/2n-5/6n-1/6m＝1／6m－14／6n＝6／1m－7／3n其中m＝6,n＝3原式＝1－7＝－6第二题一

3x-2x-x=3x-3x=0;-3a+2b-2a-3b=-3a-2a+2b-3b=-5a-b;3a^2b+4ab^2-a^2b-7ab^2=3a²b-a²b+4ab²-