Răspunsuri

2014-05-26T20:24:55+03:00
A/b= 2/5

a=2b/5

(7a-2b)/ (4a+3b)=

=(7* 2b/5 -2b) / (4* 2b/5 +3b)=

=(14b/5 -2b) / (8b/5 +3b)    aducem la acelasi numitor

=(14b-10b)/5  / (8b+15b)/5=

=4b/5 / 23b/5=

=4b/5 *5/23b=

=4/23