解方程：7x+2（3x﹣3）=20．
解：去括号得：7x+6x﹣6=20，
移项、合并同类项得：13x=26，
系数化为1得：x=2．
Nowadays more people realize the importance of health and________health is wealth has been accepted by most of us.
My mother has a lot of ____ ____ ____.
若函数f(x)=x2+ax+b有两个不同的零点x1,x2，且1<x1<x2<3，那么在f(x1),f(x2)两个函数值中 ( )
