Question

1
If 3x +1/3x
= 3, find :
9x²+1/9x²​

Answer 1

Step-by-step explanation:

${(3x + \frac{1}{3} )}^{2} = {3}^{2} \\ 9 {x}^{2} + { \frac{1}{9 {x}^{2} } } + 2 \times 3x \times \frac{1}{3x} = 9 \\ 9 {x}^{2} + \frac{1}{9 {x}^{2} } = 9 - 2\\ 9 {x}^{2} + \frac{1}{9 {x}^{2} } = 7$