Sagot :
[tex]4 \frac{1}{5}+ b = 9 \frac{3}{5} \ \ | (-4\frac{1}{5})\\ \\4 \frac{1}{5 }-4 \frac{1}{5}+ b = 9 \frac{3}{5}-4 \frac{1}{5}\\ \\b= 5\frac{2}{5}=5.4[/tex]
[tex] 4 \frac{1}{5} + b = 9 \frac{3}{5} \\\\b= 9 \frac{3}{5}-4 \frac{1}{5} \\\\b=5 \frac{2}{5} [/tex]