It should be 14, because 8 - 2 = 6 and 12 - 4 = 8
F (5x^2 - 1) = 75x^4 - 35x^2 + 6
Inversely proportional: z = k/r
k = 32 * 1.5 = 48
Plug that into equation
8 = 48/r
Multiply both sides by r
8r = 48
Divide by 8
r = 6

<h3>x = 21/5</h3>
Step-by-step explanation:
<h3>___________________________</h3>
<h3>Given →</h3>
5x:9 = 7:3
<h3>So,</h3>
→ 5x/9 = 7/3
→ x = (7 × 9)/(3 × 5)
→ x = 21/5
<h3>___________________________</h3>
<h3>Hope it helps you!!</h3>