⁶/60-Х=¹³/60-⁹/60
⁶/60-Х=⁴/60
Х=⁶/60+⁴/60
Х=¹⁰/60
⁸/100+Х=²⁰/100-⁵/100
⁸/100+Х=¹⁵/100
Х=¹⁵/100-⁸/100
Х=⁷/100
⁶/60-Х=¹³/60-⁹/60
⁶/60-Х=⁴/60
Х=⁶/60+⁴/60
Х=¹⁰/60
⁸/100+Х=²⁰/100-⁵/100
⁸/100+Х=¹⁵/100
Х=¹⁵/100-⁸/100
Х=⁷/100