Mom is 24 years older than Xiao Ming, three times his age. How old are they this year?

Mom is 24 years older than Xiao Ming, three times his age. How old are they this year?

Xiaoming's age: 24 ^ (3-1), = 24 ^ (2), = 12 (years old), mother's age: 12 + 24 = 36 (years old), answer: mother is 36 years old, Xiaoming is 12 years old

The range of y = 3x ^ 2 + 6x + 7

Y=3X^2+6X+7= 3(X^2+2X+1)+4 = 3(X+1)^2+4≥4
Range [4, + ∞)

Three years ago, the sum of the ages of father and son was 49. Now the age of father is four times that of son. How old are father and son this year?

If the son's age is x, then the father's age is 4x. Then three years ago, the son's age was x-3, the father's age was 4x-3, 4x-3 + x-3 = 49, & nbsp; & nbsp; & nbsp; & nbsp; 5x-6 = 49, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 5x = 49 + 6, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp

Find the range y = x + (x ^ 2 + 3x + 2) ^ 0.5

y-x=（x^2+3x+2)^0.5>0
The X in the root must be x > - 1, X-1, X

Father and son are 44 years old. Four years ago, father's age is eight times that of son's. how old are father and son this year?

44-8=36
36*9=4
4*8=32
36-32=4
4 + 4 = 8 (sub)
44-8 = 36 (father)
The son is 8 years old and the father is 36 years old

Find the range of y = - X-2 √ (x ^ 2 + 3x + 4)

Y = - X-2 √ (x ^ 2 + 3x + 4) y + x = - 2 √ (x ^ 2 + 3x + 4) y ^ 2 + x ^ 2 + 2yx = 4 (x ^ 2 + 3x + 4) 3x ^ 2 + (12-2y) x + (16-y ^ 2) = 0 discriminant △ = (12-2y) ^ 2-4 * 3 (16-y ^ 2) = 16y ^ 2-48y-48 ≥ 0y ≥ (3 + √ 21) / 2, or, y ≤ (3 - √ 21) / 2 range: (- ∞), (3 - √ 21) / 2] u [(3 + √ 21) / 2, + ∞)

Four years ago, the age of a father was three times that of his son. Four years later, the sum of the ages of a father and his son is 48. What are the ages of a father and his son?

Four years ago, his son was 10 years old and his father was 30 years old
Four years later, the son was 14 and the father 34

Solve the range of y = 3x / (x ^ 2 + 4)

When x = 0, y = 0, when x is not equal to 0, y = 3 / (x + 4 / x) because x + 4 / X ≥ 4 or ≤ - 4 (take equal when x = 4 / x), so 0 ＜ 1 / (x + 4 / x) ≤ 1 / 4 or - 1 / 4 ≤ 1 / (x + 4 / x) ＜ 0, that is, 0 ＜ y = 3 / (x + 4 / x) ≤ 3 / 4 or - 3 / 4 ≤ y = 3 / (x + 4 / x) ＜ 0. In conclusion, the range of Y is [- 3 / 4,3 / 4]

Four years ago, the father's age was three times that of his son. Four years later, the sum of father's and son's ages is 48. What's the age of father and son?

Four years ago, the father's age was 3x and the son's was 3x
Four years later
3x+4+x+4=48
The solution is x = 10
Now the father is 34 and the son is 14

Y = x + 2 / 3x + 4

It should be: y = (x + 2) / (3x + 4)
Range: (- ∞, 2 / 5]