令t=3^x>0
则方程化为:3t+t^2-18=0
(t+6)(t-3)=0
t=-6(负根舍去）或3
因此有3^x=3
得：x=1
猜你喜欢
- 1only to find out in the end that it was never meant to be and you just .
- 232767转换成16进制数,用降幂方法来算.会的帮下忙,
- 3they hope to learn some Chinese,too.意思
- 4今年的产量比去年的产量增加了20%，就是说今年的产量是去年的_%
- 5如图，CD⊥AB，BE⊥AC，垂足为D、E，BE、CD相交于点O，OB=OC，求证：∠1=∠2．
- 6用乐字组词（乐 在前面 ）
- 7一列数：1,-1／3,1／6,-1／10,1／15······,则第100个数是多少
- 850mL的98％浓硫酸（密度为1.84g/mL）有多少克硫酸
- 927(x+5)三次方-64=0
- 10however ,it is not what culture is that makes it so important and fascinating;