Question

(x-1)(3x-15) - 36 = 0.​

Answer 1

Ответ:

7; -1

Пошаговое объяснение:

(x-1)(3x-15) - 36 = 0.​

3х²-18х+21=0

3(х-7)(х+1)=0

х-7=0

х=7

х+1=0

х=-1

Answer 2

To solve the quadratic equation $(x-1)(3x-15) - 36 = 0$, you can follow these steps:

1. Expand and simplify the left side of the equation:

   $(x-1)(3x-15) - 36 = 3x^2 - 15x - 3x + 15 - 36 = 3x^2 - 18x - 21$

2. Now, the equation becomes:

   $3x^2 - 18x - 21 = 0$

3. Divide the entire equation by the greatest common factor, which in this case is 3, to simplify it further:

   $x^2 - 6x - 7 = 0$

4. To solve this quadratic equation, you can use the quadratic formula, which is $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$, where $a$, $b$, and $c$ are the coefficients of the equation $ax^2 + bx + c = 0$.

   In this case, $a = 1$, $b = -6$, and $c = -7$.

5. Plug these values into the quadratic formula:

   $x = \frac{-(-6) \pm \sqrt{(-6)^2 - 4(1)(-7)}}{2(1)}$

6. Simplify further:

   $x = \frac{6 \pm \sqrt{36 + 28}}{2}$

   $x = \frac{6 \pm \sqrt{64}}{2}$

   $x = \frac{6 \pm 8}{2}$

7. Now, you have two possible solutions:

   a) $x = \frac{6 + 8}{2} = \frac{14}{2} = 7$

   b) $x = \frac{6 - 8}{2} = \frac{-2}{2} = -1$

So, the solutions to the equation $(x-1)(3x-15) - 36 = 0$ are $x = 7$ and $x = -1$.