X=600。 That is, learn to buy 600 Jin of rice.
2. Assuming that the expenditure is less than x%, the equation (48+32) x% = 32 is obtained according to the meaning of the question, and x=40 is obtained by solving the equation.
That is, mom spends 40% less.
Suppose the growth this year is x% higher than last year. According to the meaning of the question, we can get the equation (1+x%) (11) =11,and we can get x by solving the equation.
4. Let the oil in the original barrel be x kg, and get the equation according to the meaning of the question.
86-x = 38-40% x, solve this equation and get x=80, that is, the oil in the original barrel is 80 kg.
5. Let this book * * * have x pages, and get the equation 20%x+12=50%x according to the meaning of the question, and get x=40 when solving the equation, that is