Пошаговое объяснение:
1. а) 49x - x^2 = 0
x(49 - x) = 0
x = 0
x = 49
б) x^2 - 9 = 0
(x - 3)(x + 3) = 0
x = -3
x = 3
в) 2x^2 - 7x + 5 = 0
D = 7^2 - 4*2*5 = 49 - 40 = 9
x = (7+3)/4 = 2.5
x = (7 - 3)/4 = 1
2. а) x^2 + 6x + 5 =
x1 + x2 = -6
б) x1 + x2 = -3
3. (х - 2)(х - 3) = 0
x^2 - 5x + 6 = 0
4. x1 + x2 = -5/3
x1 = -2
x2 = -5/3 +2 =1/3
x1 * x2 = k/3
k = 3*x1*x2 = 3*(-2)*1/3 = -2
5. x1 + x2 = 5
3x1 + 3x2 = 15
3x1 + 2x2 = 12
x2 = 15 - 12 = 3
x1 = 5 - 3 =2
