Answer:
C
Step-by-step explanation:
To solve this use the equation [tex]x^2 -15x - 50 = y[/tex] given in the problem and the value y = 50. Substitute y = 50 then solve for x by factoring.
[tex]x^2 -15x - 50 = 50\\x^2 - 15x -100 = 0[/tex]
Find two numbers which multiply to -100 and also add to -15. The numbers are -20 and 5.
So the factored form is (x-20)(x+5) = 0.
Set each factor equal to 0 and solve.
(x-20) = 0 so x = 20.
(x+5)=0 so x = -5.
This means the temperature is 20 degrees C or -5 degrees C. Only 20 is an option. The solutions is C.
