[tex] \sf{\qquad\qquad\huge\underline{{\sf Answer}}} [/tex]
Let's Solve ~
[tex]\qquad \sf \dashrightarrow \: 4 {x}^{2} + 20x + 25[/tex]
[tex]\qquad \sf \dashrightarrow \: 4 {x}^{2} + 10x + 10x + 25[/tex]
[tex]\qquad \sf \dashrightarrow \: 2x(2x + 5) + 5(2x + 5)[/tex]
[tex]\qquad \sf \dashrightarrow \: (2x + 5) (2x + 5)[/tex]
[tex]\qquad \sf \dashrightarrow \: (2x + 5) {}^{2} [/tex]
or
[tex] \sf{\qquad \sf \dashrightarrow \: 4x² + 20x + 25 } [/tex]
[tex] \sf{\qquad \sf \dashrightarrow \: (2x)² + (2 \sdot 2x \sdot 5) + (5)²} [/tex]
[ it's similar to expression - a² + 2ab + b² that is equal to (a + b)² ]
so, let's use this identity here to factorise :
[tex] \sf{\qquad \sf \dashrightarrow \: (2x + 5)²} [/tex]
I hope it was helpful ~