若（x³）⁵=2¹⁵×3¹⁵，则x=____．

 下列关于物质组成与分类的说法中正确的是（　　）​

任务型阅读Sunshine Clothes Store
     Hi, boys and girls! Please come to our store. We have white and blue socks for $3.The black hat is only $4.The T-shirt is on sale for only $6.We have red T-shirts, white T-shirts and black T-shirts. The white sweater is $8, the red sweater is $9 and the blue sweater is $10.We also have black trousers and blue trousers. They are $11.The shorts are $14, and the shoes are $14, too.

卤族元素的单质和化合物很多，我们可以利用所学物质结构与性质的相关知识去认识和理解它们．

已知向量$\overrightarrow{a}$=(2,1),$\overrightarrow{b}$=(3,λ)，若$\overrightarrow{a}$$\perp$$\overrightarrow{b}$，则λ=____