Question 550565
Steve is 25 years older than his son John. In ten years, Steve will be twice John's age. How old are Steve and John now? Write a system of equations to model the situation. 
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Equation:
s = j + 25
(s+10) = 2(j+10)
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Substitute for "s" and solve for "j":
(j+25+10) = 2j+20
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j+35 = 2j+20
j = 15 (John's age now)
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Solve for "s":
s = j+25
s = 15+25 = 40 (Steve's age now)
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Cheers,
Stan H.