Answer:
[tex]b = 7.9[/tex]
Step-by-step explanation:
[tex]5 + (9.7 - b) = 6.8 \\ 5 + 9.7 - b = 6.8 \\ 14.7 - b = 6.8 \\ - b = 6.8 - 14.7 \\ - b = - 7.9 \\ = b = 7.9[/tex]
