下图中,阴影部分的面积甲比乙多57平方厘米,AB的长为20厘米,求CB的长。:]/C:^0k-I
解答 设CB的长为x厘米。:]/C:^0k-I
算式:提示'R8u-f'J2F;J9F-e7]-e,W2^7U1l:]/C:^0k-I
答:CB的长为+t,R.N2x0s8r厘米。:]/C:^0k-I