Question 185260
When Sarah was born her mother was 23. In three more years Sarah's mother will be twice Sarah's age now. How old are they now?
:
M = Mom's age now; S = Sarah's age now
:
"When Sarah was born her mother was 23."
M = S + 23
:
In three more years Sarah's mother will be twice Sarah's age now.
M + 3 = 2(S + 3)
M + 3 = 2S + 6
M = 2S + 6 - 3
M = 2s + 3
:
 How old are they now?
Substitute (S+23) for M in the above equation
S + 23 = 2S + 3
23 - 3 = 2S - S
S = 20 yrs Sarah's age now
then
20 + 23 = 43 yrs is Mom's age now
;
;
Check solution:
In three more years Sarah's mother will be twice Sarah's age now.
43 + 3 = 2(20 - 3)
46 = 2(23)


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