Question

m的平方减2m减1等于0，则代数式2m的平方减4m加3等于几？

Answer 1

Answer 2

m²-2m-1=0
∴m²-2m=1
∴2m²-4m+3
=2(m²-2m)+3
=2×1+3
=5

Answer 3

5
m²-2m-1=0
m²-2m=1
2m²-4m+3=5

Answer 4

因为：m^2+m-1=0所以,乘以m得到：m^3+m^2=mm^3+2m^2+2011=m^2+m+2011=1+2011=2012