a²+2ab+12b =a(a+2b)+12b =6a+12b =6(a+2b) =6×6=36 这部怎么来的a²+2ab+12b =a(a+2b)+12b

a²+2ab+12b =a(a+2b)+12b =6a+12b =6(a+2b) =6×6=36 这部怎么来的a²+2ab+12b =a(a+2b)+12b
a²+2ab+12b =a(a+2b)+12b =6a+12b =6(a+2b) =6×6=36 这部怎么来的a²+2ab+12b =a(a+2b)+12b

a²+2ab+12b =a(a+2b)+12b =6a+12b =6(a+2b) =6×6=36 这部怎么来的a²+2ab+12b =a(a+2b)+12b
你的题目是不是有写a+2b=6,
如果有写,那你就写因为a+2b=6
所以a(a+2b)+12b =6a+12b

提取公因式a