(x+12)X(x十12)=xXx十360

问题描述:

(x+12)X(x十12)=xXx十360

(x+12)x(x+12)=xx+360
x(x+12)+12x+12x12=xx+360
xx+12x+12x+144=xx+360
24x+144=360
24x=216
x=9