Problem7x=217x = 217x=21分步解答两边同除以 777:x=217x = \frac{21}{7}x=721。化简:x=3x = 3x=3。答案x=3x = 3x=3想解其他题?打开 linear 求解器 →相关例题/solve/algebra/2x-plus-3-equals-7