Respuesta :
Answer:
Option D [tex]x^{2} -x-6=0[/tex]
Step-by-step explanation:
Verify each quadratic equation
case A) we have
[tex]x^{2} +x+6=0[/tex]
This quadratic equation has a leading coefficient of 1
Substitute the value of x=3 and x=-2 in the equation
For x=3
[tex](3)^{2} +(3)+6=0[/tex]
[tex]18=0[/tex] ----> is not true
therefore
x=3 is not a solution of the quadratic equation
case B) we have
[tex]x^{2} -x-5=0[/tex]
This quadratic equation has a leading coefficient of 1
Substitute the value of x=3 and x=-2 in the equation
For x=3
[tex](3)^{2} -(3)-5=0[/tex]
[tex]1=0[/tex] ----> is not true
therefore
x=3 is not a solution of the quadratic equation
case C) we have
[tex]x^{2} +x+5=0[/tex]
This quadratic equation has a leading coefficient of 1
Substitute the value of x=3 and x=-2 in the equation
For x=3
[tex](3)^{2} +(3)+5=0[/tex]
[tex]17=0[/tex] ----> is not true
therefore
x=3 is not a solution of the quadratic equation
case D) we have
[tex]x^{2} -x-6=0[/tex]
This quadratic equation has a leading coefficient of 1
Substitute the value of x=3 and x=-2 in the equation
For x=3
[tex](3)^{2} -(3)-6=0[/tex]
[tex]0=0[/tex] ----> is true
therefore
x=3 is a solution of the quadratic equation
For x=-2
[tex](-2)^{2} -(-2)-6=0[/tex]
[tex]4+2-6=0[/tex]
[tex]0=0[/tex] ----> is true
therefore
x=-2 is a solution of the quadratic equation