Question 818129
What is the formlae for the following:- 
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Mary is 3 yrs younger than Bob who is going to be x years old a year from now. How old is Mary now?
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Equations:
m = b-3
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b = x-1
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Substitute and solve for "m":
m = (x-1)-3 = x-4 (Mary's age now)
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Cheers,
Stan H.
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