Solution:
[tex]\text{Area of square = L}^{2} \ \ \ \ \ \text{(L = Side)}[/tex]
[tex]\rightarrow \text{Area of square} = (3x^{2} - 5)^{2}[/tex]
Using the formula "(a + b)² = a² + 2ab + b²"
[tex]\rightarrow \text{Area of square} = (3x^{2} )^{2} - 2(3x^{2} )(-5) + 5^{2}[/tex]
Simplifying the LHS:
[tex]\rightarrow \text{Area of square} = (3x^{2} )(3x^{2} ) +(30x^{2} ) + 25[/tex]
[tex]\rightarrow \boxed{\text{Area of square} = 9x^{4} +30x^{2} + 25}[/tex]
