Răspunsuri

2014-01-20T19:04:08+02:00
A-b=20,4
a-5/4(1 si 1/4)=5b
Inlocuim a in ecuatie
5b+1,25(5/4)-b=20,4
4b=20,4-1,25
b=19,15/4
b=4,7875

a=20,4+4,7875
a=25,1875 :D
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2014-01-20T19:15:17+02:00
A-b=20,4 
1 intreg 1/4+a=5b
5/4+a=5b
(5+4a)/4=20b/4
5+4a=20b
a=(20b-5)/4⇒ a=5b-5/4
inlocuim pe a in relatia a-b=20,4
(5b-5/4-b=20,4) *4(reducem numitorul)
20b-5-4b=81,6
16b=86,6
b=5,4125
a=5,4125+20,4⇒ a=25,8125


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