The father is 47 years old and the son is 21 years old. A few years ago, the father was three times as old as the son?

Suppose that x years ago, the father was three times as old as his son
According to the meaning of the title:
(47-X)/(21-X)=3
The solution is x = 8
A: eight years ago, the father was three times as old as his son
It's your fault that you can't give such a good answer

The father is 47 years old and the son is 21 years old. A few years ago, the father was three times as old as the son?
I don't know how to use XY. Can you answer without XY? Thank you

Calculation method: the specific calculation method is as follows:
This year, the father is 47 years old, the son is 21 years old, the difference is 26 years old, this is a constant
That means the father is 27 and the son is one
We can see that the father is 39 years old and the son is 13 years old, just three times
That is to say, 47-39 = 8 years ago

My father is 32 years older than my son this year. Four years later, my father is five times older than my son. How old is my son this year?

Suppose the age of my son is x years old after four years. From the meaning of the question, I get: 5x-x = 32 & nbsp; & nbsp; 4x = 32 & nbsp; & nbsp; & nbsp; X = 88-4 = 4 years old. A: my son is four years old this year

My father is 32 years older than my son. Two years later, my father is five times older than my son. How old is my son?
Such as the title

If his son is x years old, his father is (x + 32) years old
5(x+2)=(x+32)+2
The solution is x = 6

The father is 32 years older than his son this year. Three years later, the father's age is five times that of his son. How old is his son this year?
You can't use equations

The son is 5 years old and the father is 37 years old. Three years later, the son is 8 years old and the father is 40 years old, which is five times as old as 40 years old

The father is 32 years older than his son this year. Three years later, the father's age is five times that of his son. How old is his son this year?

Oh, 32 + X + 3 = (3 + x) 5, do it yourself

1/2+(1/3+2/3)+1/4+2/4+3/4)+...+(1/40+2/40+...+38/40+39/40)=?

Original formula = 1 / 2 + 3 / 3 + 6 / 4 + 10 / 5 + 15 / 6 +... + (1 + 39) * 39 / 2 / 40
=0.5+1+1.5+2+2.5…… +19.5
=（0.5+19.5）*39/2
=390

2 / 1 + (3 / 1 + 3 / 2) + (4 / 1 + 4 / 2 + 4 / 3) +. Omitted + (60 / 1 + 60 / 2 + 60 / 3. + omitted 60 / 58 + 60 / 59)
Ha ha, no points!

=1/2+2/2+3/2+.+59/2
=59*(59+1)/4=885

2 / 3 + 3 / 4 + 4 / 5 + + +. + 38 / 39 + 39 / 40 =?

37.57

1. Decompose the following factors: ① 9A & # 178; - 6ab + 3A; ② the fourth power of M - 18m & # 178; N + 81n & # 178;

①9a²-6ab+3a
=3a(3a-2b+1)
② The fourth power of M - 18m & # 178; N + 81n & # 178;
=(m²-9n)²
If you don't understand this question, you can ask,

The father is 47 years old and the son is 21 years old. A few years ago, the father was three times as old as the son?