Algebra review

Question

Jody's older brother is only three years less than twice jody's age. If there sum of their agesis 30, then what age is jody's brother?

Answer 1

 

There will be two unknowns, so you should look for two equations.

 

   Let  j=Jody's age  &   b=older brother's age

 

 b = 2j-3    (1)   (Jody's older brother is only three years less than twice Jody's age)

 j+b = 30   (2)   (sum of their ages is 30)

 

Can you solve?   Hint: eq(1) shows b in terms of j,  can that be used in eq(2)?