问题
填空题
若3y2+y-2的值为5,则6y2+2y-2的值为______.
答案
6y2+2y-2=2(3y2+y-1),
∵3y2+y-2=5,
∴3y2+y=7,
代入6y2+2y-2得,
6y2+2y-2=2(3y2+y-1)
=2(7-1)
=12.
故答案为12.
若3y2+y-2的值为5,则6y2+2y-2的值为______.
6y2+2y-2=2(3y2+y-1),
∵3y2+y-2=5,
∴3y2+y=7,
代入6y2+2y-2得,
6y2+2y-2=2(3y2+y-1)
=2(7-1)
=12.
故答案为12.