Question

一道初二解方程

81x²-100=0
求x的值，写过程

Answer 1

81x²-100=0
81x²=100
x²=100/81
x=10/9或x=-10/9

Answer 2

81x²=100
x²=100/81
x=zheng fu 10/9

Answer 3

81x2=100
x2=100/81
x=+_10/9