S = a² - 4b² = (a + 2b)(a - 2b) = (9.82 + 2×2.41)×(9.82 - 2×2.41) = 14.64×5 = 73.2(平方厘米)答:剩余部分的面积是73.2 平方厘米
列式:a2-4b2当a=9.28.b=2.41=(a-4b)(a+4b)=
A2-B2=(A+B)(A-B)