设□为x,于是此题转化为解关于x的方程,
162×[( 4
1
7 -700x)÷ 1
2
7 ]=81,
162×[( 4
1
7 -700x)÷ 1
2
7 ]÷162=81÷162,
( 4
1
7 -700x)÷ 1
2
7 =
1
2 ,
( 4
1
7 -700x)÷ 1
2
7 × 1
2
7 =
1
2 × 1
2
7 ,
4
1
7 -700x=
9
14 ,
700x+
9
14 = 4
1
7 ,
700x+
9
14 -
9
14 = 4
1
7 -
9
14 ,
700x=
7
2 ,
700x÷700=
7
2 ÷700,
x=
1
200 .