Answer:
n = 9/4B + 31
Step-by-step explanation:
[tex]B=\frac{4}{9}(n-31)\\\\\frac{9}{4}(B)=(\frac{4}{9}(n-31))\frac{9}{4}\\\\\frac{9}{4}B=n-31\\\\\frac{9}{4}B+31=n-31+31\\\\\frac{9}{4}B+31=n[/tex]
