Recursive equation simple calculation, application problem, equation problem 27.42-（5.7+4.42） 16.5-0.25×5-7.25 An iron wire can be enclosed into a square with an area of 49 square centimeters. If it is enclosed into a rectangle with a width of 4 centimeters, calculate the area of the rectangle 3×（x-7）=0.6 Plus a practical problem. From place B to place a, the price of a plane is four times that of a train, and the price of a plane ticket is 1050 yuan more expensive than that of a train ticket. How much is the price of a plane ticket and a train ticket? (solution of a series of equations) Ask to answer completely, add unit, see clearly number sign.

Recursive equation simple calculation, application problem, equation problem 27.42-（5.7+4.42） 16.5-0.25×5-7.25 An iron wire can be enclosed into a square with an area of 49 square centimeters. If it is enclosed into a rectangle with a width of 4 centimeters, calculate the area of the rectangle 3×（x-7）=0.6 Plus a practical problem. From place B to place a, the price of a plane is four times that of a train, and the price of a plane ticket is 1050 yuan more expensive than that of a train ticket. How much is the price of a plane ticket and a train ticket? (solution of a series of equations) Ask to answer completely, add unit, see clearly number sign.

27.42 - (5.7 + 4.42) = 27.42-5.7-4.42 = 27.42-4.42-5.7 = 23-5.7 = 17.3 16.5-0.25 × 5-7.25 = 16.5-1.25-7.25 = 16.5 - (1.25 + 7.25) = 16.5-8.5 = 8 an iron wire can be enclosed into a square with an area of 49 square centimeters. If it is enclosed into a rectangle with a width of 4cm, find the surface of the rectangle