Question

(3x - 1) (3x + 1) - (x - 1) (x + 2) = 8.​

Answer 1

Ответ:

Объяснение:

Вот через дискриминант

Answer 2

To solve the equation (3x - 1)(3x + 1) - (x - 1)(x + 2) = 8, we can start by expanding the expressions on both sides and simplifying the equation.

Expanding the left side: (3x - 1)(3x + 1) - (x - 1)(x + 2) = (9x^2 - 1) - (x^2 + x - 2) = 9x^2 - 1 - x^2 - x + 2

Combining like terms: = (9x^2 - x^2) + (-1 - x + 2) = 8x^2 - x + 1

Now we can rewrite the equation as: 8x^2 - x + 1 = 8

To solve this quadratic equation, we can rearrange it to have zero on one side: 8x^2 - x - 7 = 0

Now, we can either factor the quadratic equation or use the quadratic formula to find the solutions. Let's use the quadratic formula:

x = (-b ± √(b^2 - 4ac)) / (2a)

For the quadratic equation 8x^2 - x - 7 = 0, the coefficients are: a = 8, b = -1, and c = -7.

Substituting these values into the quadratic formula: x = (-(-1) ± √((-1)^2 - 4 * 8 * -7)) / (2 * 8) x = (1 ± √(1 + 224)) / 16 x = (1 ± √225) / 16 x = (1 ± 15) / 16

Simplifying: x = (1 + 15) / 16 or x = (1 - 15) / 16

x = 16/16 or x = -14/16 x = 1 or x = -7/8

Therefore, the solutions to the equation (3x - 1)(3x + 1) - (x - 1)(x + 2) = 8 are x = 1 and x = -7/8.