Question 309778: 1. rose is 6yrs older than her sister in four years she will be nine years more than one half as old as her sister, how old are they now?
2. edwin is twice as old as ruel, in three years edwin will be 13 years less than twice as old as ruel, find their present ages?
3. susan is 4/5 as old as ronald, four years ago she was 3/4 as old as ronald, how old is each?
4. edwin is four years older than his brother alwin, in two years edwin will be 20 more than 1/3rd alwins age, how old are the brothers now?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! I will give a step-by-step solution on the 1st problem, then give the equations on the last 3:
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1. rose is 6 yrs older than her sister in four years she will be nine years
more than one half as old as her sister, how old are they now?
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Write an equation for each statement
"rose is 6 yrs older than her sister"
r = s + 6
:
"in four years she will be nine years more than one half as old as her sister,"
r + 4 = .5(s+4) + 9
r + 4 = .5s + 2 + 9
r + 4 = .5s + 11
r = .5s + 11 - 4
r = .5s + 7
Replace r with s+6 from the 1st statement
s + 6 = .5s + 7
s - .5s = 7 - 6
.5s = 1
multiply both sides by 2
s = 2 is the sisters age
then
r = .5s + 7
r = .5(2) + 7
r = 1 + 7
r = 8 is Roses age
:
Check solution in the statement:
"in four years she will be nine years more than one half as old as her sister,
8 + 4 = .5(2 + 4) + 9
12 = .5(6) + 9
12 = 3 + 9; confirms our solution
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;
2. edwin is twice as old as ruel,
in three years edwin will be 13 years less than twice as old as ruel,
find their present ages?
This is not a valid problem, no solution here
:
:
3. susan is 4/5 as old as ronald,
s =  r
four years ago she was 3/4 as old as ronald,
s - 4 =  (r-4)
how old is each?
:
:
4. edwin is four years older than his brother alwin,
e = a + 4
in two years edwin will be 20 more than 1/3rd alwins age,
e + 2 =  (a+2) + 20
how old are the brothers now?
:
See if you can solve the last two using the 1st one as an example,
if you need more help, let me know in the comment section.
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