Answer:
[tex]x= -5 or x = 4[/tex]
Solution Set = {-5, 4}
Step-by-step explanation:
[tex]x^{2} + x -20 = 0[/tex]
[tex]x^{2} + 5x - 4x -20 = 0[/tex]
[tex](x^{2} + 5x) - (4x + 20) = 0[/tex]
[tex]x(x + 5) - 4(x + 5) = 0[/tex]
[tex](x + 5)(x - 4) = 0[/tex]
[tex]x+ 5= 0 or x - 4 = 0[/tex]
[tex]x= -5 or x = 4[/tex]
Solution Set = {-5, 4}