Question

已知2m的平方—1=-m，求2m的3次方＋5m的2次方＋m

已知2m的平方—1=-m，求2m的3次方＋5m的2次方＋m

Answer 1

2m的平方—1=-m，
2m²=-m＋1
2m²＋m=1
2m的3次方＋5m的2次方＋m
=m（-m＋1）＋5m²＋m
=4m²＋2m
=2×1
=2

Answer 2

2m的平方—1=-m，
2m²=-m＋1
2m²＋m=1
2m的3次方＋5m的2次方＋m
=2m3+m²+4m²+m
=m(2m²＋m)+( 2m²＋m)+2m²
=m+1+2m²
=( 2m²＋m)+1
=1+1
=2