Question

Mă ajutați vărog la punctul:C?

Answer 1

$\frac{9}{13}$ - $\frac{2}{13}$ - $\frac{5}{13}$ + $\frac{11}{13}$ = $\frac{13}{13}$
$\frac{7}{13}$ - $\frac{5}{13}$ + $\frac{11}{13}$ = $\frac{13}{13}$
$\frac{2}{13}$ + $\frac{11}{13}$ = $\frac{13}{13}$
 $\frac{13}{13}$ = $\frac{13}{13}$ = 1