Correct

一元方程

/ yī yuán fāngchéng / 
Strokes

Example

As a Noun

equation with one unknown quantity

1
Yī
一
yuán
元
yī
一
cìfāngchéng
次方程

linear equation in one unknown

2
Yīyuánèrcìfāngchéng
一元二次方程

quadratic equation in one variable; a single variable quadratic equation