如果x+2y=3 7x+5y=-1,那么(4x+8y)/3+(14x+10y)/2=?急!
问题描述:
如果x+2y=3 7x+5y=-1,那么(4x+8y)/3+(14x+10y)/2=?
急!
答
(4x+8y)/3+(14x+10y)/2=3
答
x+2y=3 7x+5y=-1,
∴(4x+8y)/3+(14x+10y)/2
=4/3×﹙x+2y)+(7x+5y)
=4/3×3-1
=4-1
=3