I dont understand this, please give an explanation

Answer:
[tex]\bold\blue{x {}^{2} + 5x + 4} [/tex]
Here ,
we just need to substitute " x = - 5 " in the equation above.
[tex]\bold{x {}^{2} + 5x + 4} \\\bold{ ( - 5) {}^{2} + 5( - 5) + 4} \\ \bold{ \cancel{25} - \cancel{25} + 4} \\ \fbox\pink{⇢ 4}[/tex]
hope helpful ~
[tex] \huge \qquad \boxed{ \sf Aᥒsᥕᥱr ☂}[/tex]
let's plug in the value of x as -5, in the given expression ~
[tex] \qquad\rightarrowtail \sf {x}^{2} + 5x - 4[/tex]
[tex] \qquad\rightarrowtail \sf { (- 5)}^{2} + 5( - 5) - 4[/tex]
[tex] \qquad\rightarrowtail \sf 25 - 25 + 4[/tex]
[tex] \qquad\rightarrowtail \sf 4[/tex]
Therefore, we got the required value 4