已知ab=-3,a b=2,求2a² 2b²
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ab(a^2b^5-ab^3-b)=a^3b^6-a^2b^4-ab^2=(ab^2)^3-(ab^2)^2-ab^2=6³-6²-6=216-36-6=174
(3a-4b-ab)-(a-2b+3ab)=3a-4b-ab-a+2b-3ab=2a-2b-4ab=2(a-b)-4ab=2×(-1)-4×(-2)(将a-b=-1,ab=-2代入)=-2+8=6
(3a+5ab)-(3ab-3b)=3a+5ab-3ab+3b=3a+3b+2ab=3(a+b)+2ab代入:3*3+2*(-2)=5本题不用求出a、b的值,这属于一道可以用简便算法的题
ab^2=-2-ab(a^2b^5-ab^3-b)=-a^3b^6+a^2b^4+ab^2=-(ab^2)^3+(ab^2)^2+ab^2=-(-2)^3+(-2)^2+(-2)=8+4-2=10
a^2+ab=3,b^2+ab=7a^2-ab-2b^2=a^2+ab-2ab-2b^2=(a^2+ab)-2(ab+b^2)=3-2×7=-11
a2+2ab+b2=(a2+ab)+(ab+b2)=-2+6=4
ab^2=-6所以-ab(a^2*b^5-ab^3-b)=-a^3b^6+a^2b^4+ab^2=-(ab^2)^3+(ab^2)^2+(ab^2)=-(-6)^3+(-6)^2+(-6)=216+3
ab(36b-6b-b)=29ab^2=(30-1)*6=174
ab(ab^3+a^2b^5-b)=ab²(ab²+a²b^4-1)=6*(6+6²-1)=6*41=246
ab+2ab+ab=ab(a+2ab+b)∵a+b=2/3,ab=2,∴原式=2×(2/3+2×2)=28/3爱执着
ab+2ab+ab=ab(a+2ab+b)∵a+b=2/3,ab=2,∴原式=2×(2/3+2×2)=28/3
a^2b+ab^2=ab(a+b)=21(a+b)^2=7^2a^2+b^2+2ab=49a^2+b^2=49-6=43
已知ab=3,a+b=4,3ab-[2a-(2ab-2b)+3]的值=3ab-2a+2ab-2b-3=5ab-2(a+b)-3=5×3-2×4-3=15-8-3=4;很高兴为您解答,skyhunter
明显a=2b=-1,代入.
2a^2b+ab^2-3a^b+5ab-2ab^2-3ab=-a^2b-ab^2+2ab=-ab(a+b)+2ab=-10×1+2×10=10
2(ab-3a)-3(2b+ab)=2ab-6a-6b-3ab=-ab-6(a+b)=-3-6*2=-15
a^2+3ab+2b^2=(a^2+ab)+2X(ab+b^2)=4-2=2
2[ab+(-3a)]-3(2b-ab)=2[ab-3a]-6b+3ab=2ab-6a-6b+3ab=2ab+3ab-6a-6b=5ab-6(a+b)=5*3-6*(-4)=15+24=39
(1)将其提取因式ab,原式=ab(a2+2-b2)=2(a2+2-b2),而将a+b平方再减去4ab,得(a-b)的平方=41,则a-b=根号41,再代入原式可得答案:4+14根号41(2)因为n(