Question 753887

Jeff is 7 years older than Marty. The sum of their ages is 71. How old is Marty


Let Marty's and Jeff's ages be M, and J, respectively


Then: J = M + 7 ----- eq (i)


Also, J + M = 71 ------ eq (ii)


While a few methods can be used to solve this system, namely, substitution, elimination, graphing, etc., the easiest method HERE is that of substitution.


M + 7 + M = 71 ------ Substituting M + 7 for J in eq (ii)


2M = 64


M, or Marty's current age = {{{64/2}}}, or {{{highlight_green(32)}}}


You can do the check!!


Send comments and “thank-yous” to “D” at MathMadEzy@aol.com