SOLUTION: Trevor is 6 years older than Miranda. In 8 years the sum of their ages will be 60. How old is Trevor now?

From the condition, you have these two equations

T = M + 6             (1)   ("Trevor is 6 years older than Miranda.")

(T+8) + (M+8) = 60    (2)   ("In 8 years the sum of their ages will be 60.")



Substitute the expression (1) for T into eq(2). You will get


((M+6) + 8) + (M+8) = 60


2M + 6 + 8 + 8 = 60


2M + 22 = 60  ====>  2M = 60 - 22 = 38  ====>  M =  = 19.


Then  T = M + 6 = 19+6 = 25.


Answer.  M = 19,  T = 25.