Repede vă rog!!!
Dau coroană!!!!!!

Explicație pas cu pas:
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a) n/12=5/6=6×n=5×12=6n=60=n=60÷6=n=10
b)35/n=5/6=5×n=35×6=5n=210÷5=n= 42
c).n+1/18=5/6=6x(n+1)=18×5=6n+6=90=6n=90-6=6n=84=n=84÷6=n=14
d) 30/2n+4=5/6=5×(2n+4)=30×6=10n+20=180=10n=180-20=10