未知数用英语怎么说？

未知数

例句

• His ability to make decisions in a crisis is an unknown quantity. 他在危机中作决定的能力还是个未知数。
• You must eliminate an unknown quantity. 你必须消去一个未知数。
• It was like a single equation with two unknowns. 这挺像两个未知数组成了个简单方程.
• The length of the war is one of the biggest unknowns. 战争要持续多久是最大的未知数之一。
• In algebra, the sign X usually denotes an unknown quantity. 在代数里, 符号X常用来表示未知数.
• He is an unknown quantity for his rivals. 对于对手们而言，他是个未知数。