Respuesta :
Answer:
D. No solutions.
Step-by-step explanation:
We have been given a system of equations and we are asked to find the solution set for our given system.
[tex]y=x^2-4x-21[/tex]
[tex]y=-5x-22[/tex]
To find the solution for our given system we will equate our both equations as:
[tex]x^2-4x-21=-5x-22[/tex]
[tex]x^2-4x+5x-21=-5x+5x-22[/tex]
[tex]x^2+x-21=-22[/tex]
[tex]x^2+x-21+22=-22+22[/tex]
[tex]x^2+x+1=0[/tex]
We will use discriminant formula to check for the solution of our given system.
[tex]\sqrt{b^2-4ac} \geq 0[/tex] for real solutions.
Upon substituting our given values in above formula we will get,
[tex]\sqrt{1^2-4*1*1} \geq 0[/tex]
[tex]\sqrt{1-4} \geq 0[/tex]
[tex]\sqrt{-3} \ngeq 0[/tex]
Therefore, our given system has no solutions and option D is the correct choices.