Question

Срочно нуждаюсь)Очень нужна ваша помощь

Answer 1

Ответ:

2

a)

$x^{2} +5x+4=0\\D = 25-4*4 = 25-16 = 9\\x_{1} = \frac{-5+3}{2} = -1\\x_{2} = \frac{-5-3}{2} = -4$

б)

$y^{2} - 9y + 20 = 0\\ D = 81-4*20 = 81-80 = 1\\y_{1} = \frac{9+1}{2} = 5\\ y_{2} = \frac{9-1}{2} = 4$

3 a)

$x_{1} = 2 \\ x_{2} = 5$

$(x-2)(x-5) = x^{2} -5x -2x+10 = x^{2} -7x+10$

б)

$x_{1} = -0.2\\x_{2} = -10\\(x+0.2)(x+10) = x^{2} +10x+0.2x+2 = x^{2} +10.2x+2$

Answer 2

2. а) x²+5x+4=0

x₁+x₂=-5

x₁·x₂=4

x₁=-4; x₂=-1;

б) y²-9y+20=0

y₁+y₂=9

y₁·y₂=20

y₁=5; y₂=4;

3. а) x²-7x+10=0

б) y²+10.2y+2=0