My father is 39 years old and my son is 11 years old. Q: how many years later will my father be three times as old as his son

Arithmetic method: 39-11 = 28
Since it will be three times in a few years, it means twice as much
28 / 2 = 14, so that's double 14
14-11 = 3, so 3 years later
I don't know. Are you clear?
Equation, let X be three times
39+x=3(11+ x)
x=3

Function f (x) = x ^ 2-6x + 11

From F (x) = x ^ 2-6x + 11 = (x-3) ^ 2 + 2
So the function f (x) = x ^ 2-6x + 11 has a range of [2, + infinity]

My son is 13 years old. My father is 40 years old. Is there a year when my father is four times as old as his son?

In the year of X, the father's age is exactly four times of his son's. The answer is: x = - 4. Four years ago, the father's age was exactly four times of his son's

Find the function y = x + 1 / x, X belongs to the range of [- 3, - 2]

y=x+1/x
x=-3,y=-3-1/3=-10/3
x=-2,y=-2-1/2=-5/2
Y range [- 10 / 3, - 5 / 2]

My son is 13 years old and my father is 40 years old. Is there a year when my father is four times as old as my son? Why?

After X years,
40+X=(13+X)*4
40+X=52+4X
The 3x = - 12 equation produces a negative number, so it doesn't

If the value range of function y = log (2) (AX & # 178; + 2x + 1) is r, then the value range of a is?

If the range is r, then the range of G (x) = ax ^ 2 + 2x + 1 contains all positive numbers
When a = 0, G (x) = 2x + 1
When A0, we need △ > = 0, i.e. 4-4a > = 0, to get a

The son is 13 years old and the father is 40 years old. Is it possible that in a certain year, the father's age is four times the son's age?
A detailed explanation of the question is helpful for the respondent to give an accurate answer

Yes
After X years, the father's age is 4 times the son's age
That is, (40 + x) / (13 + x) = 4, x = - 4
So when the father is 40-4 = 36, the son is 13-4 = 9
36/9=4
The father is four times the son's age

My son is 13 years old. My father is 40 years old. Is there a year when my father is four times as old as his son?

In the year of X, the father's age is exactly four times of his son's. The answer is: x = - 4. Four years ago, the father's age was exactly four times of his son's

My son is 13 years old and my father is 40 years old. Is there any year that is four times the age of my son? Why

4×（13＋X）=40＋X

My father is 47 years old and my son is 21 years old. How many years ago, my father was three times as old as my son

The practice of primary school students:
21 - (47-21) / (3-1) = 8 (years old)

My father is 39 years old and my son is 11 years old. Q: how many years later will my father be three times as old as his son