[30-(x-10)]² 等于几,紧急答

[30-(x-10)]² 等于几,紧急答
[30-(x-10)]² 等于几,紧急答

[30-(x-10)]² 等于几,紧急答
解[30-(x-10)]^2
=[30-x+10]^2
=（40-x）^2
=（x-40）^2
=x^2-80x+1600

-xx-80x+1600

拆开算就好了，用公式（a-b)²=a²-2ab+b²
X²-80X+1600