Question 333745
Let m = mother's present age
Let d = daughter's present age (Marty)
:
Write an equation for each statement:
;
Marty is 1/3 as old as her mother.
d = {{{1/3}}}m
or we can say
m = 3d
:
Five years ago she was only 1/5 of the age of her mother.
d - 5 = {{{1/5}}}(m-5)
Mult both sides by 5, get rid of that fraction
5(d-5) = m - 5
5d - 25 = m - 5
5d = m - 5 + 25
5d = m + 20
Replace m with 3d
5d = 3d + 20
5d - 3d = 20
2d = 20
d = 10 yrs is Marty
:
:
check solution in the statement; m = 3(10) = 30 is mom
"Five years ago she was only 1/5 of the age of her mother.
10 - 5 = {{{1/5}}}(30 - 5)