Question 66860
Let s = sally's age now; j = john's age now
:
Write an equation for each statement. just like it says:
"Five times sally's age now exceeds 3 times John's age by 30." 
5*s = (3*j) + 30
or
5s = 3j + 30
:
"In 10 years, twice sally's age will exceed john's age by 26."
:
Their ages in 10 years would be (s+10) and (j+10), right?
:
A simple equation from this statement:
2(s+10) = (j+10) + 26
2s + 20 = j + 36
2s + 20 - 36 = j
2s - 16 = j
Or
j = (2s - 16)
:
Remember our 1st equation; 5s = 3j + 30. Substitute (2s-16) for j, find s
5s = 3(2s-16) + 30
5s = 6s - 48 + 30
5s - 6s = 48 + 30
-1s = -18
s = 18 yrs is sally's age now
:
Find John's age now
j = 2s - 16
j = 2(18) - 16
j = 36 - 16
j = 20 yrs is john's age now
;
 What will be their ages 13 years from now?
Sally will be 31 and John will be 33

:
Check in the 2nd equation: 2(s+10) = (j+10) + 26
2(18+10) = 20 + 10 + 26
2(28) = 56
:
Did this make some sense to you? Any questions?