Question

Aflati nr.natural n pt.care sunt echivalente fractiile:a)2n supra 5 si n+3 supra 3,b)7 supra 4n si 3 supra n+5;c)n+7 supra 5 si 3n supra 8,d)6 supra n+4 si 9 supra 2n

Answer 1

a) 2n/5=n+3/3=> 2n×3=(n+3)×5=> 6n=5n+15=> n=15
b)7/4n=3/n+5=> 7n+35=12n=> -5n=-35=> -n=-7=> n=7
c)n+7/5=3n/8=> 8n+56=15n=> -7n=-56=> -n=-8, n=8
d) 6/n+4=9/2n => 12n=(n+4)×9=> 12n=9n+36=> 3n=36=> n=12