Question

Este O poza cu problema... daca scriu imi ia mult, va rog repede!! dau coroana​

Answer 1

Răspuns:

Explicație pas cu pas:

Answer 2

$\it a)\ \ \dfrac{x}{28}=\dfrac{^{4)}3}{\ 7} \Rightarrow \dfrac{x}{28}=\dfrac{12}{28} \Rightarrow x=12\\ \\ \\ b)\ \dfrac{45}{x}=\dfrac{^{15)}3}{\ 7} \Rightarrow \dfrac{45}{x}=\dfrac{45}{105} \Rightarrow x=105\\ \\ \\ c)\ \dfrac{2x+1}{21}=\dfrac{^{3)}3}{\ 7} \Rightarrow \dfrac{2x+1}{21}=\dfrac{9}{21} \Rightarrow 2x+1=9|_{-1} \Rightarrow 2x=8 \Rightarrow x=4\\ \\ \\ d)\ \dfrac{51}{38+x^2}= \dfrac{3}{7}|_{:3} \Rightarrow \dfrac{17}{38+x^2}=\dfrac{1}{7} \Rightarrow 38+x^2=119|_{-38} \Rightarrow x^2=81$

$\it x=\pm9$