Question

Determinati nr nat. x pentru care fractiile sunt echiunitare :
2x-1 supra 15

21 supra 2x+1

x+1 supra 2x

5x supra
a x+8

2x+1 supra x+4
Plss ! Coroana ! Am nevoie de ajutor !

Answer 1

   
[tex]\displaystyle \\ \texttt{Fractiile echiunitare au numaratorul egal cu numitorul.} \\ \\ a)~ \frac{2x-1}{15}=1 ~~\Rightarrow~~ 2x-1 = 15 ~~\Rightarrow~~ 2x = 16 ~~\Rightarrow~~x = \frac{16}{2}=\boxed{8} \\ \\ b)~ \frac{21}{2x+1}=1~~\Rightarrow~~2x+1=21~~\Rightarrow~~ 2x=20 ~~\Rightarrow~~x= \frac{20}{2} =\boxed{10} \\ \\ c)~ \frac{x+1}{2x} =1~~\Rightarrow~~2x=x+1~~\Rightarrow~~2x-x=1~~\Rightarrow~~x=\boxed{1}[/tex]


[tex]\displaystyle \\ d)~ \frac{5x}{x+8}=1~~\Rightarrow~~5x=x+8~~\Rightarrow~~ 4x=8~~\Rightarrow~~x= \frac{8}{4}=\boxed{2} \\ \\ e)~ \frac{2x+1}{x+4}=1~~\Rightarrow~~2x+1=x+4~~\Rightarrow~~2x-x=4-1~~\Rightarrow~~x=\boxed{3} [/tex]