SOLUTION: hi need answer by Thursday so please be quick. I really need someone's help. question: Phil is x years old. his sister's age is 1/4 of his age. Their father is 31 years older

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Question 1088822: hi need answer by Thursday so please be quick. I really need someone's help.
question:
Phil is x years old. his sister's age is 1/4 of his age. Their father is 31 years older than Phil's sister.
a)If their father is 35 years old form an equation in terms of x.
b)Find Phil's age.
Found 2 solutions by josgarithmetic, jim_thompson5910:
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
x, Phil's age
s, his sister's age
y, their father's age

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Phil is x years old. his sister's age is 1/4 of his age. Their father is 31 years older than Phil's sister.
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system%28s=x%2F4%2Cy=x%2F4%2B31%29


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a) If their father is 35 years old form an equation in terms of x.
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Simple substitution. You do this and simplify.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Part A)

P = phil's age
S = sister's age
F = father's age

We're told that Phil is x years old, so P = x

Phil's sister is 1/4 of Phil's age, so S = (1/4)*P = (1/4)*x = 0.25x
In short, S = 0.25x

Their father is 31 years older than Phil's sister, so F = S+31 = 0.25x+31
In short, F = 0.25x+31

Replace F with 35 because we're told that the father is 35 years of age.

The answer to part A is 35 = 0.25x+31

Note: you can use the fraction 1/4 in place of 0.25

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Part B)

Solve the result found in part A for x.

35 = 0.25x+31

35-31 = 0.25x+31-31 ... subtact 31 from both sides

4 = 0.25x

4/0.25 = 0.25x/0.25 ... divide both sides by 0.25

16 = x

x = 16

Phil is 16 years old