2.235²+0.765×4.47+0.765²
=2.235² +(3-2.235)*(2*2.235)+(3-2.235)²
=(2.235+3-2.235)²
=9
2.235²×0.765×4.47²+0.765² 怎么用简便运算?可能应该用乘法公式计算
2.235²+0.765×4.47+0.765²
=2.235² +(3-2.235)*(2*2.235)+(3-2.235)²
=(2.235+3-2.235)²
=9