要做一个容积为750cm^3,高为6cm,底边长比宽多5cm
问题描述：
要做一个容积为750cm^3,高为6cm,底边长比宽多5cm
答
设底边宽为x厘米,则底边长为x+5厘米.
x(x+5)*6 = 750
x^2+5x = 125
(x+5/2)^2 = 125 + 25/4
(x+5/2)^2 = 525/4
x+5/2 = (5根号21) /2
x = 根号21 / 2