Answer:
[tex]\large \text{Part a:}\\\\for\ d<0:\ \boxed{v<-\dfrac{25}{d}}\\\\for\ d>0:\ \boxed{v>-\dfrac{25}{d}}[/tex]
[tex]\large\text{Part b:}\\\\\boxed{r=\dfrac{7}{3}w-5}[/tex]
Step-by-step explanation:
[tex]\text{Part a}\\\\-vp+40<65\qquad\text{subtract 40 from both sides}\\\\-vp<25\qquad\text{change the signs}\\\\vp>-25\qquad\text{divide both sides by }\ d\neq0\\\\\text{if}\ d>0,\ \text{then}\ \boxed{v>-\dfrac{25}{d}}\\\\\text{if}\ d<0,\ \text{then you must flip the inequality symbol}\ \boxed{v<-\dfrac{25}{d}}[/tex]
[tex]\text{Part b}\\\\7w-3r=15\qquad\text{subtract 7w from both sides}\\\\-3r=-7w+15\qquad\text{divide both sides by (-3)}\\\\\boxed{r=\dfrac{7}{3}w-5}[/tex]
