a平方+a-3=0 a四次+2a三次-a-1=tell me please 3q

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a平方+a-3=0 a四次+2a三次-a-1=tell me please 3q
a平方+a-3=0 a四次+2a三次-a-1=
tell me please 3q

a平方+a-3=0 a四次+2a三次-a-1=tell me please 3q
a^2+a-3=0
a^2+a=3
a^4+2a^3-a-1
=a^2*(a^2+a)+a^3-a-1
=a^3+3a^2-a-1
=a*(a^2+a)+2a^2-a-1
=2a^2+2a-1
=2(a^2+a)-1
=5

a^4+2a^3-a-1
=a^4+a^3-3a^2+a^3+a^2-3a+2a^2+2a-6+5
=a^2(a^2+a-3)+a(a^2+a-3)+2(a^2+2a-3)+5
=0+0+0+5
=5