已知x+2y=6,则3x+6y—3=?
问题描述:
已知x+2y=6,则3x+6y—3=?
答
3x+6y-3
=3(x+2y-1)
=3×(6-1)
=15
已知x+2y=6,则3x+6y—3=?
3x+6y-3
=3(x+2y-1)
=3×(6-1)
=15