brad is 2 years older than pedro. five years ago pedro was 3/4 brads age. what are their present ages?

Question

How do I create the equation from this? I don't understand what to do with the five years ago part

 

Answer 1

Let's set Brad's current age as B and Pedro's current age as P.

We know from the first sentence that Brad is 2 years older than Pedro. Thus:

B = P + 2

The second sentence says: 5 years ago, Pedro's age was 3/4 of Brad's age.

To denote 5 years ago, we must subtract 5 years from both Brad's current age and Pedro's current age:

B - 5 & P - 5

We know that 5 years ago, Pedro's age was 3/4 of Brad's age. Thus:

 

P - 5 = (3/4) (B - 5)

 

Now, you have two equations and two unknowns:

B = P + 2

&

P - 5 = (3/4) (B - 5)

 

Hope it goes well.

Answer 2

b = Brad's age

p = Pedro's age

 

Brad is 2 years older than Pedro:

b = p+2

 

5 years ago Pedro was 3/4 of Brad's age:

(3/4)(b-5) = p - 5

(3/4)b - 15/4 = p-5

3b - 15 = 4(p-5)

3b - 15= 4p - 20

3b - 4p = -5

 

We know b = p+2

substitute that into 2nd equation

 

3(p+2) - 4p = -5

3p + 6 - 4p = -5

-p = -11

p = 11

 

b = p + 2 = 13

 

Brad is 13, Pedro is 11