Question

Question #51db4

Answer 1

Christianson is 18 years old and Yroak is 12 years old.

Explanation:

`C` : Present age of Christianson,
`Y` : Present age of Yroak,

Christianson is now 6 years less than twice the age of Yroak.

`C = 2Y - 6` ...... (1)

At 9 years age, Christianson was 3 times as old as Yroak. This means Yroak was 3 years old then. Let us assume that this was `X` years from the present.

`C = 9 + X; \qquad Y = 3 + X \qquad \rightarrow X = Y - 3;`
Eliminate `X` in one equation using the other
`C = 9 + (Y - 3) = 6 + Y` ...... (2)

Comparing (1) and (2)
`2Y - 6 = 6 + Y; \qquad \rightarrow Y = 12`

Therfore, `C = 2Y - 6 = 18`

Answer 2

Please see answers and steps below...

Explanation:

Let yroak's age be `= x`

Hence we will used yroak age as the basis, to interpret the rest statement..

Christianson is now `6yrs` less than twice the age of yroak..

`6yrs` less means `(x - 6)yrs` where `x` is yroak's age

Bu since yroak's age was twice, hence the expression is;

Expression: `(2x - 6)yrs`

Is it nine years ago or nine years after???

Well I'll interpret it separately..

Christianson was 3 times as old as yroak

If its' For Nine years ago

yroak's age `= x - 9`

Christianson's age `= 3(2x - 6) - 9`

If its' For Nine years after

yroak's age `= x + 9`

Christianson's age `= 3(2x - 6) + 9`

Remember yroak's age still remains unknown `x`, so we are using Christianson's age to find yroak's age..

We will equate both ages together...

`x - 9 = 3(2x - 6) - 9 ->` For `9yrs` ago!

Expanding the brackets..

`x - 9 = 6x - 18 - 9`

Simplifying..

`x - 9 = 6x - 27`

Collecting like terms..

`x - 6x = - 27 + 9`

`-5x = -18`

`cancel- 5x = cancel- 18`

`x = 18/5`

`x = 4yrs` "which is not possible.."

`x + 9 = 3(2x - 6) + 9 ->` For `9yrs` after!

Expanding the bracket..

`x + 9 = 6x - 18 + 9`

Simplifying..

`x + 9 = 6x +9`

`x + cancel9 = 6x + cancel9` "which is also not possible..

Please rephrased the statement!