15ц4/19*х+3ц17/19*х=21ц2/19
19ц2/19*х=21ц2/19
х=21ц2/19:19ц2/19
х=401/19:363/19
х=401/19*19/363
х=401/363
х= 1ц38/363
=>15+3+1+x+2/19=21+2/19=>
=>19+x=21=>
=>x=21-19=>
=>x=2;
ответ:2.
15ц4/19*х+3ц17/19*х=21ц2/19
19ц2/19*х=21ц2/19
х=21ц2/19:19ц2/19
х=401/19:363/19
х=401/19*19/363
х=401/363
х= 1ц38/363