Answer:
see explanation
Step-by-step explanation:
Given
y = [tex]\frac{s}{2x^3}[/tex] ← multiply both sides by 2x³
2x³y = s ← substitute x = 3[tex]y^{4}[/tex] into left side, then
2[tex](3y^4)^{3}[/tex] y = s, thus
s = 2 × 3³ × [tex]y^{12}[/tex] y
= 2 × 27 × [tex]y^{(12+1)}[/tex]
= 54[tex]y^{13}[/tex]