X^2+2x-80=0 4x^+4x+1=0 3y^2-3y+1=0 5x^2=9x+2

Question

X^2+2x-80=0
4x^+4x+1=0
3y^2-3y+1=0
5x^2=9x+2

Answer 1

1) D= 2²-4*1*(-80)=4+320=324
x1=-2+√324/2=-2+18/2=16/2=8
x2=-2-18/2=-20/2=-10
2) D=4²-4*4*1=16-16=0
x1=0
3) D=(-3)²-4*3*1=9-12=-3
нет кореней
4) 5x²-9x-2=0
D=(-9)²-4*5*(-2)=81+40=121
x1=9+√121/2*5=9+11/10=20/10=2
x2=9-11/10=-2/10=-1/5