已知a的平方-a-1=0,求a三次方减2a加2017的值-搜答案-神马作文网

a^3+2a^2+2a+1=(a^3+a^2+a)+(a^2+a+1)=a(a^2+a+1)+(a^2+a+1)=a*0+0=0

a²-3a=-1a的立方-a的平方-5a+2007=a(a²-3a)+2a²-5a+2007=-a+2a²-5a+2007=2(a²-3a)+2007

∵a的平方-3a-1=0a-3-1/a=0a-1/a=3(a-1/a)²=3²a²-2+1/a²=9∴a²+1/a²=11

a的平方-4a+1=0等式两边同除aa-4+1/a=0a+1/a=4因为a+1/a=4所以(a+1/a)^2=4^2a^2+2+1/a^2=16a^2+1/a^2=16-2=14(a-a分之一)的平方

a平方+3a-1=0,a≠0,两边同除以a得:a+3-1/a=0a-1/a=-3(a-1/a)²=9a²+1/a²-2=9a²+1/a²=11(a+1

解(a-1/a)=1两边平方(a-1/a)²=1即a²-2+1/a²=1∴a²+1/a²=3

由a^2+a-3=0得a^2+a=3a^3+2a^2-2a+1=a^3+a^2+a^2-2a+1=a(a^2+a)+=3a+a^2-2a+1=a^2+a+1=3+1=4

把a^2-3a+1=0两边都除以a,得,a+1/a=3所以(a-1/a)^2=a^2+1/a^2-2=(a+1/a)^2-4=3^2-4=9-4=5

a^2+a-1=0a^2+a=1a^3+a^2=aa^3+2a^2+2=a^3+a^2+a^2+2=a+a^2+2=1+2=3

a²-3a+1=0两边除以aa-3+1/a=0a+1/a=3两边平方a²+2+1/a²=9a²+1/a²=7

应该是a³-2a+2009a²-a-1=0a²=a+1所以a³=a(a²)=a(a+1)=a²+a=(a+1)+a=2a+1所以原式=2a+

已知：a^2-5a+1=0a1=2.5+(2.5^2-1)^0.5=2.5+(5.25)^0.5a2=2.5-(2.5^2-1)^0.5=2.5-(5.25)^0.5a1^2=2.5^2+2*2.5*

a^2-5a+1=0,a+1/a=5a^4+a^2+1/a=a(a^3+a+1/a+1/a^3)-1=a((a+1/a)^3-2(a+1/a))-1=a(5^3-2*5)-1=115*a-1a^2-5

a²-5a+1=0a²+1=5a平方(a²+1)²=25a²a^4+2a²+1=25a²a^4+a²+1=24a

a平方-4a+1=0a^2+1=4a(a^2+1)^2=16a^2a^4+1+2a^2=16a^2a^4+1=14a^2(a的4次方+a平方+1)/a^2=(14a^2+a^2)/a^2=15a^2/

(a²+b²-1)²=9(a²+b²-1)²-9=0(a²+b²-1-3)(a²+b²-1+3)=0

由题目知道a^3+a^2=a,a^2+a=1上面两个式子相加得a^3+2a^2=1所以a^3+2a^2+3=1+3=4

a平方+4a+1=0∴a+4+1/a=0∴a+1/a=-4两边平方得a²+2+1/a²=16a²+1/a²=14(3a的三次方+a平方+3a)分之（a四次方+a

a^2-3a+1=0等式两边同除以aa-3+1/a=0a+1/a=3a^2+1/a^2=(a+1/a)^2-2=3^2-2=7(a-1/a)^2=(a+1/a)^2-4=3^2-4=5再问：倒着的尖的

a+1/a=2(a+1/a)^2=a^2+1/a^2+2=4a^2+1/a^2=4-2=2a^2-3a+1=0a+1/a=3(a+1/a)^2=a^2+1/a^2+2=9a^2+1/a^2=9-2=7