T(t+3)+t^2-9=0 решите пж:(

Question

T(t+3)+t^2-9=0 решите пж:(

Answer 1

t(t+3)+t^2-9=0
t^2+3t+t^2-9=0
2t^2+3t-9=0
D=b^2-4ac=3^2-4*2*(-9)=9+72=81=9^2
x1=(-b-√D)/2a=-3; 
x2=(-b+√D)/2a=3/2