Răspuns:
[tex]\displaystile\bf\\ (((a+20)-180:47)*32+19*25)-258=569\\\\((a+20)-180:47)*32+475=569+258\\\\((a+20)-180:47)*32 = 827 - 475\\\\((a+20)-180:47)*32 = 352 \:\:\:\: /:32\\\\(a+20)-180:47 = 11\:\:\:\: /*47\\\\47*(a+20) -180 = 517\\\\47a+940 = 517+180\\\\47a=697-940\\\\47a=-243\\\\a=-243:47\\\\\boxed{\displaystile\bf\ a=-\frac{243}{47}}[/tex]