144

Ա) 7>3X – 5X²

5X²+2X+3>0

Բ) 2X > -3 +2X²

2X²+2X+3>0

Գ) 13X² -5<X

13X² – X-5>0

Դ) 4X +5>X²

-X² +4X+5>0

Ax²  + bx + c = 0

D = b² – 4ac

ա) 2x² + 5 +3 = 0

D = 25 – 4 × 2  3 = 0

D= 25-4 × 2  3 = 4 × 2  3 = 25-24 =1

D=1

Բ) 2x² + 5x – 3 =0

D= 25 – 4 × 2  3 = 0

D= 25 – 4 × 2  3 = 25 – 4 × 2  3 =  25 – 24 = 1

D = 1

Գ) 2x² + 5x -3 =0

 D= 25 – 4 × 2  (-3) = 0

D= 25 – (-24) = 49

D= 49

Դ) 2x² + 5x  — 3 = 0

D= 25 – 4 × 2  (-3) = 0

D= 25 – 4 × 2 (- 3) = 0

D= 25 – 4 × 2  (-3) = 25 – (-24 ) = 49

D= 49

137

ա) x²-x+3>0

x²-x+3=0

D=1-4*1*3=1-12= -11

բ) x²+2x+2<0                               

x²+2x+2=0

D=4-4*1*2= -4

գ) x² -3x+4<0

x²-3x+4=0

D=9-4*1*4= -7

դ) x²+x+5<0

    x²+x+5=0

   D=1-4*1*5= -19