Given that \( y = \left(\frac{pr}{m} - p^2r\right)^{-\frac{3}{2}} \) (a) make r the subject; (b) find the value of r when y = -8, m = 1 and p = 3.

(a) y =(prm−p2r $\frac{\mathrm{<br>}}{}$)−32 ${}^{\frac{<br>}{}}$ 

y−23 ${}^{\frac{-2}{3}}$  =(prm−pr2
)

my−23 ${}^{\frac{-2}{3}}$  =(pr−pr2mm $\frac{\mathrm{<br>}}{}$)

my−23 ${}^{\frac{-2}{3}}$ = pr - p2 ${}^{\mathrm{<br>}}$rm

my−23 ${}^{\frac{-2}{3}}$ = r(p - p2 ${}^{\mathrm{<br>}}$m)

r = (my−2/3m−p2m $\frac{\mathrm{<br>}}{}$)

(b) r = (1−8−2/33−32∗1
)

= 14 $\frac{1}{4}$ ÷ -6

= - 1−6 $\frac{\mathrm{<br>}}{}$

= - 124