Odpowiedź :
x + 1,25x + x + 8 = 50
3,25x + 8 = 50 /-8
3,25x = 42 /:3,25
x ~ 13 cm
[tex]a - x\\b - 1,25x\\c - x+8\\Ob = a+b+c\\50 = x+1,25x+x+8\\50=3,25x+8\\42=3,25x \\42=3\frac{1}{4}x\\42=\frac{13}{4}x /*4\\168=13x /:3\\\frac{168}{13}=x\\x=12\frac{12}{13}cm[/tex]