Grandma is 64 years old and grandson is 13 years old. How many more years will grandma be four times as old as grandson?
Let's suppose that after another x years, grandma's age is four times that of her grandson. From the meaning of the question, we can get (13 + x) × 4 = 64 + X & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 52 + 4x = 64 + X & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 3x = 12 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp