Current location - Training Enrollment Network - Mathematics courses - Page 79 of the first volume of the excellent mathematics learning plan for the sixth grade has been strengthened and improved.
Page 79 of the first volume of the excellent mathematics learning plan for the sixth grade has been strengthened and improved.
Suppose the weight of oil is x kilograms, then the weight of barrel is (50-x) kilograms.
According to "After using 40%, the remaining oil drum weighs 30.8kg", it can be known that engine oil is used, so the reduced weight is 0.4xkg.. Column equation: