当x=( “)时,代数式(x-3)²的值是16 a+b=4,ab=1,则2a+3ab+2b等于
问题描述:
当x=( “)时,代数式(x-3)²的值是16 a+b=4,ab=1,则2a+3ab+2b等于
答
(x-3)²=16 x-3=±4 x=7或x=-1
2a+3ab+2b=2a+2b+3ab=2(a+b)+3ab 根据已知得原式=11