Question #51db4

2 Answers
Nov 22, 2017

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

Nov 22, 2017

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!