SOLUTION: steven is 13 years older than his sister sarah. together they are 28 years old. how old is steven and how old is sarah? pleaseeee help me i need this done for my math summer hom

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Question 624555: steven is 13 years older than his sister sarah. together they are 28 years old. how old is steven and how old is sarah?
pleaseeee help me i need this done for my math summer homework! im going into sixth grade! please help and thank you!
Found 2 solutions by solver91311, josmiceli:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Let represent the girl's age, and then her brother must be years old.



Solve for , then calculate

John

My calculator said it, I believe it, that settles it
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Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a = Steven's age
Let +b+ = Sarah's age
given:
(1) +a+=+b+%2B+13+
(2) +a+%2B+b+=+28+
---------------
Substitute (1) into (2)
(2) +b+%2B+13+%2B+b++=+28+
(2) +2b+%2B+13+=+28+
Subtract +13+ from both sides
(2) +2b+=+28+-+13+
(2) +2b+=+15+
(2) +b+=7.5+
and, since
(1) +a+=+b+%2B+13+
(1) +a+=+7.5+%2B+13+
(1) +a+=+20.5+
Steven is 20 yrs 6 mos old
Sarah is 7 yrs 6 mos old
check answer:
Do ages add up to +28+ ?
Is the difference +13+ ?
Yes