Respuesta :
[tex]\qquad\qquad\huge\underline{\boxed{\sf Answer}}[/tex]
Let's solve ~ ☂
[tex]\qquad \sf \dashrightarrow \: {x}^{2} + 4x - 77[/tex]
[tex]\qquad \sf \dashrightarrow \: {x}^{2} + 11x - 7x - 77[/tex]
[tex]\qquad \sf \dashrightarrow \: {x}^{} (x + 11) -7(x + 11)[/tex]
[tex]\qquad \sf \dashrightarrow \: {}^{} (x + 11)(x - 7)[/tex]
Answer:
x = 7
x = -11
Step-by-step explanation:
x² + 4x = 77
Complete the square to make it a square of a binomial
x² + 4x + 4 = 77 + 4
(x+2)² = 81
Square root both sides (two solutions)
x + 2 = 9
x = 7
x + 2 = -9
x = -11
Hope this helps :)
Have a nice day!