括号正7.8括号加括号负6括号加大括号负9又5分之4大括号等于几 .急.

问题描述:

括号正7.8括号加括号负6括号加大括号负9又5分之4大括号等于几 .急.

9又5分之四等于9.8 (+7.8)+(-6)+(-9 *4/5) =7.8-6-9.8 =7.8-9.8-6 =-2-6 = -8