- #1

harpazo

- 208

- 16

- Homework Statement
- Find John's current age using algebra.

- Relevant Equations
- x - 5 = (1/2)(x + 8)

Five years ago, John’s age was half of the age he will be in 8 years. How old is he now?

John's age now = x

John's age 5 years ago = x - 5

John's age in 8 years = x + 8

x - 5 = (1/2)(x + 8)

x - 5 = (x/2) + 4

2(x - 5) = 2[(x/2) + 4]

2x - 10 = x + 8

2x - x = 8 + 10

x = 18

John is currently 18 years old.

Let me check.

Let x = 18

18 - 5 = (1/2)(18 + 8)

13 = (1/2)(26)

13 = 13

It checks to be true.

John's age now = x

John's age 5 years ago = x - 5

John's age in 8 years = x + 8

x - 5 = (1/2)(x + 8)

x - 5 = (x/2) + 4

2(x - 5) = 2[(x/2) + 4]

2x - 10 = x + 8

2x - x = 8 + 10

x = 18

John is currently 18 years old.

Let me check.

Let x = 18

18 - 5 = (1/2)(18 + 8)

13 = (1/2)(26)

13 = 13

It checks to be true.