Question

(27/39-х)+15/39=17/39

Answer 1

25/39-х=17/39-15/39
25/35-х=2/39
х=25/39-2/39
х=23/39

Answer 2

Ответ:

$(\frac{27}{39}-x )+\frac{15}{39}=\frac{17}{39};$

[ сократим первую дробь на 3 - разделим 27 на 3 и 39 на 3 ]

$(\frac{9}{13}-x )+\frac{15}{39}=\frac{17}{39};\\\\ \frac{9}{13}-x +\frac{15}{39}=\frac{17}{39};$

[ сократим дробь  $\frac{15}{39}$  на 3 ]

$\frac{9}{13}-x +\frac{5}{13}=\frac{17}{39};\\\\ \frac{14}{13}-x =\frac{17}{39};\\\\ -x =\frac{17}{39}-\frac{14}{13};\\\\ -x =\frac{17}{39}-\frac{14*3}{39};\\\\ -x =\frac{17}{39}-\frac{42}{39};\\\\ -x =-\frac{25}{39}; | : (-1)\\\\ x =\frac{25}{39}.$