Question

grandpa's age is 6 yrs less than 6 times junior's age. the sum of their age is 78. find each of their ages

Answer 1

ok, grandma's represents y, jr is x.
you have to equations,
y = 6x-6 (grandma's age)
and x + y = 78.
here, you have to do substitution.
so... y = 78 - x.
from there you set that equal to the other equation, so
78 - x = 6x - 6.
you then solve for x (junior's age) and plug that in in order to find grandma's age.
hope that helps!