Question 170510
b. so  when is robin twice as old as mary.  Take you expressions
:
robin (35+y)=2 mary's 2(12+y)
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35+y=24+2y--->combine like terms
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y=11------->so robin will be {{{35+11=46}}}and Mary will be{{{12+11=23}}}
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c. this time we have robin(35+y)=3 mary's(12+y)
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35+y=3(12+y)
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35+y=36+3y-->combine like terms
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y=-1/2  so Robin was {{{35-1/2=34.5}}} and Mary was {{{12-1/2=11.5}}}