Jeanquinto890viz
Answered

john is 6 years older than his brother.he will be twice as old as his brother in 4 years.how old is john now?

Sagot :

Dominiviz
[tex]Let \ x+6 \ be \ the \ age \ of \ John \\ Let \ x \ be \ the \ age \ of \ his \ brother \ \\ \\ x+10 \to \ age \ of \ John \ 4 \ years \ from \ now. \\ x+4 \to \ age \ of \ John's \ brother \ 4 \ years \ from \ now. \\ \\ x+10=2(x+4)[John's \ age \ in \ four \ years \ is \ twice \ as \ his \ brother.] \\ \\ x+10=2x+8[Use \ Distributive \ Property] \\ \\ 10=x+8[subtracted \ x \ from \ both \ sides] \\ \\ 2=x[subtracted \ 8 \ from \ both \ sides] \\ \\ \boxed{x=2} \\ \\ x+6 \to \boxed{8}[/tex]
Alvedeguzviz
Let x be the age of his Brother

Therefore, John's Age will be

y = 6 + x (first equation)

In 4 years

y + 4 = 2(x + 4) (second equation)

Now let's substitute the value of y from the first equation to the second equation

(6 + x) + 4 = 2(x + 4)

Add 6 and 4; Multiply 2 to x + 4

10 + x = 2x + 8

Transpose x and 8

10 - 8 = 2x - x

Therefore the age of his brother is

x = 2

Now let's substitute the value of x to the first equation

y = 6 + 2

Therefore John's age is

y = 8

Now let us check if adding 4 to both will make John's age twice as his brother

after 4 years

x = 2 + 4

x = 6

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y = 8 + 4

y = 12

12 is twice as 6. Therefore it is correct.

I hope it helps