MHB Find Kari & Jackie's Ages: 2C-13+1C=66

[DawnC]

Age question:

Kari's age is 13 less than twice Jackie's age, C. If the sum of their age is 66, find each person's age.

2c-13 = Kari
1C = Jackie

Would I sent up this question as 2C-13+1C = 66?

 

[MarkFL]

Age question:

Kari's age is 13 less than twice Jackie's age, C. If the sum of their age is 66, find each person's age.

2C-13 = Kari
1C = Jackie

Would I sent up this question as 2C-13+1C = 66?

Yes, that's correct. Now you can determine both ages. :D

 

[DawnC]

Would the next step then be?

2c -13 +1c = 3c -13 = 66 then minus 66-13?

 

[MarkFL]

Would the next step then be?

2c -13 +1c = 3c -13 = 66 then minus 66-13?

You want to remain consistent with your variable names...you began with $C$ (uppercase), so let's stick with that:

$$2C-13+C=66$$

So, yes, now combine like terms on the left:

$$3C-13=66$$

Now, our ultimate goal here is to isolate $C$ on the left, and since 13 is being subtracted on the left, how can we undo this subtraction while still maintaining the equality of both sides of the equation?

 

[Wilmer]

Kari's age is 13 less than twice Jackie's age, C. If the sum of their age is 66,

Are you sure 13 and 66 are both in original problem?
As is, ages are not integers...

 

[Nono713]

Are you sure 13 and 66 are both in original problem?
As is, ages are not integers...

Do they have to be? :D

 

[Wilmer]

Do they have to be? :D

Of course not; however, 99.9% of age problems are,
and more so in this case as the student is apparently a beginner.

 

[phymat]

Age question:

Kari's age is 13 less than twice Jackie's age, C. If the sum of their age is 66, find each person's age.

2c-13 = Kari
1C = Jackie

Would I sent up this question as 2C-13+1C = 66?

According to the question,
Age of Jackie = $c$
Age of Kari = $2c-13 \tag{1}$
Sum of their ages = $c+(2c-13)=66 \tag{2}$
Solving (2) will give you the value of $c$ (age of Jackie).
Substituting the value of $c$ in (1) will give you the age of Kari.

Where are you getting confused?