🚀 go-pugleaf

senat@sk.sympatico.ca (Guy Desautels) wrote:

>In article <3335E89E.71A8@nbnet.nb.ca>, Bill Best <kellyc@nbnet.nb.ca> wrote:

>> I am having problems with the following question. Could you please help
>> me by showing me how it is worked out. I've been through my textbook and
>> my mom has tried to figure it out..maybe I can help you in return in the 
>> near future:
>> 
>> Craig is one year less than twice as old as Colin. The sum of three times 
>> Craig's age and twice Colins's age is 45. Find their ages.  The answer is
>> Craig is 11 and Colin is 6. Please show me how they figured this out?
>> I am knew at word problems..grade 10.

>Let x = Colin
>Let y = Craig

Better would be ....Colin's age, and Craig's age.
                                         ^^^                    ^^^

>  
>            y = 2x - 1

O.K so far.

> 3(2x-1) + 2y =45

Not really.
3y + 2x = 45

Then  substitute (one method) for y to get

3(2x - 1) + 2x = 45

6x - 3 + 2x = 45

8x = 45 + 3

8x = 48

x = 48/8 = 6

y = 2x - 1 = 2*6 - 1 = 11

>Then Colin is 5 and Craig is 9
>Double check.

A wise idea.  I should do more of that myself.  Saves a lot of
headaches. :-)

David.