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9 votes
9 votes
In three years' time a pet mouse will be as old as his owner was

four years ago. Their present ages total 13 years. Find the age of
each now.

User Gurisko
by
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1 Answer

20 votes
20 votes

Answer:

owner = 10 years old

mouse = 3 years old

Explanation:

Let's say the mouse is currently m years old and the owner is currently o years old.

m + o = 13

In three years, a pet mouse (m+3) will be as old (=) as his owner was 4 years ago (o-4)

m+o=13

m+3=o-4

subtract o from both sides in the first equation to solve for m

m = 13 - o

plug 13-o for m in the second equation to isolate one variable in one equation

13-o+3=o-4

16-o=o-4

add o to both sides to put all the variables on one side

16=2o-4

add 4 to both sides to isolate the variable and its coefficient

20 = 2o

divide both sides by 2 to isolate o

o = 10

m = 13 - o

m = 3

User Amin Y
by
2.9k points