[tex] (x + 3)(x + 5)[/tex] ✅
[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]
[tex] {x}^{2} + 8x + 15 \\ ={x}^{2} + 5x + 3x + 15 [/tex]
Taking [tex]x[/tex] as common from first two terms and 3 from last two terms, we have
[tex] =x(x + 5) + 3(x + 5)[/tex]
Taking the factor [tex](x+5)[/tex] as common,
[tex] = (x + 3)(x + 5)[/tex]
[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{!}}}}}[/tex]