问题
解答题
计算:
①[(3x+y)2-y2]÷x
②10.25×9.75(用简便方法计算)
答案
①原式=(9x2+6xy+y2-y2)÷x═(9x2+6xy)÷x=9x+6y;
②原式=(10+0.25)×(10-0.25)=100-0.0625=99.9375.
计算:
①[(3x+y)2-y2]÷x
②10.25×9.75(用简便方法计算)
①原式=(9x2+6xy+y2-y2)÷x═(9x2+6xy)÷x=9x+6y;
②原式=(10+0.25)×(10-0.25)=100-0.0625=99.9375.