Question 123151
Write and equation for each statement or phrase
:
if Leah is 6 years older than her sister, Sue,
L = S + 6
:
and John is 5 years older than Leah,
J = L + 5
Substitute (S+6) for L
J = (S+6) + 5
J = S + 11
:
They are asking for Sue's age, so get the other ages in terms of S
:
and the total of their ages is 41.
L + S + J = 41
: 
Then how old is Sue?
Substitute for L and J in the above equation
(S+6) + S + (S+11) = 41
3S + 17 = 41
3S = 41 - 17
3S = 24
S = {{{24/3}}}
S = 8 yrs is Sue's age
;
:
Check solution using the total age
L = 8 + 6
L = 14
:
J = 8 + 11
J = 19
:
14 + 8 + 19 = 41