单括号展开
Expanding Single Brackets
利用乘法分配律，将括号外的单项式分别乘入括号内的每一项，从而展开（去掉）括号；例如 3(2x + 5) = 6x + 15，也包括处理含负系数的展开。
Expand (multiply out) a single term over a bracket using the distributive property, e.g., 3(2x + 5) = 6x + 15; expand expressions involving negative multipliers
学习证据 / Evidence
- 用一个正的单项式去乘括号内的每一项，从而展开表达式
- 用一个负的单项式去乘括号内的各项，并正确处理符号
- 结合展开括号与合并同类项，将表达式完全化简
- Multiply a single positive term over a bracket to expand the expression
- Multiply a negative term over a bracket, correctly handling signs
- Combine expanding brackets with collecting like terms to simplify fully
评估问题 / Assessment
{{name}}能不能把像 3(2x + 5) 这样的括号展开，将括号内的每一项都乘上外面的数，得到 6x + 15？
Can {{name}} expand a bracket like 3(2x + 5) by multiplying everything inside, to get 6x + 15?