1.直接用商的算术平方根的性质把 ab=ab (a≥ 0 ,b0 )反过来 ,得 ab= ab(a≥ 0 ,b0 )。当被除式的被开方数能被除式的被开方数整除时 ,可以运用 ab=ab(a≥0 ,b0 )进行二次根式的除法运算。例 1 .计算下列各式 :(1 ) - 1 23÷ 56;(2 ) 2 x2 y2z3 ÷ (- xy2 z)。解 :(1 ) - 1 1. Directly use the quotient’s square root of arithmetic to reverse ab=ab (a≥ 0, b0) to get ab= ab(a≥ 0, b0). When the dividend of the divided formula can be divisible by the open square of the divisor, ab=ab(a≥0, b0) can be used to perform the quadratic radical division. Example 1. Calculate the following equations: (1) - 1 23÷ 56; (2) 2 x2 y2z3 ÷ (- xy2 z). Solution :(1 ) - 1