Chapter 6 - Section 6.2 - One-to-One Functions; Inverse Functions - 6.2 Assess Your Understanding - Page 422: 91

a. $r(d)=\frac{d+90.39}{6.97},$ b. $r(d(r))=r,$ $d(r(d))=d,$ c. $r(300)=56.01$

$d(r)=6.97r-90.39,$ a. $r(d)=\frac{d+90.39}{6.97},$ b. $r(d(r))=\frac{6.97r-90.39+90.39}{6.97}=\frac{6.97r}{6.97}=r,$ $d(r(d))=6.97(\frac{d+90.39}{6.97})-90.39=d,$ c.$r(300)=\frac{300+90.39}{6.97}=56.01$