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put this solution on YOUR website!: A mother is 4 times as old as her son and in twenty years will be twice as
old as her daughter, who is five years older than her brother. How old is each?
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Let their present ages = m, b, s; for mother, brother, and sister
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write an equation for the given statements:
"A mother is 4 times as old as her son"
m = 4b
:
"in twenty years (she) will be twice as old as her daughter,"
m + 20 = 2(s+20)
m + 20 = 2s + 40
m - 2s = 40 - 20
m - 2s = 20
:
"who is five years older than her brother."
s = (b + 5)
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How old is each?:
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In the equation: m - 2s = 20:
substitute 4b for m and (b+5) for s
4b - 2(b+5) = 20
4b - 2b - 10 = 20
2b = 20 + 10
2b = 30
b =
b = 15 is the brothers age
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you can find the other ages using the equations for m and s,
Check your solutions in the statement:
"In twenty years mother will be twice as old as her daughter,
:
:
Let me know if you have any questions about this?
