Question

factorise 84-2x-2x²

Answer 1

Hello friend
---------------
Your answer
-------------------

★ FACTORISATION
------------------------------

84 - 2x - 2x²

= - 2x² - 2x + 84

= - 2x² - (14 -12)x + 84

= - 2x² - 14x + 12x + 84

= - 2x(x + 7) + 12(x + 7)

=> (x + 7)(- 2x + 12)

= -2(x - 6)(x + 7)

HOPE IT HELPS

Answer 2

Given,

• $84-2x-2x^2$ is given

To find,

• factors of $84-2x-2x^2$

Solution,

The factors of  $84-2x-2x^2$ are (x-6) and (x+7).

We can simply factorize the given quadratic equation $84-2x-2x^2$ by using the quadratic formula.

                          = $84-2x-2x^2$

Taking (-) common from the equation, we get

                          = $2x^2 +2x-84$

                      D = b²-4ac

                      D = (2)² - 4(2)(-84)

                      D = 4 + 672

                      D = 676

                     x = -b±√D/2a

                      x = -2±$\sqrt{676}$ / 2 (2)

                      x = -2 ± 26 / 4

                      x = -7 and x = 6

∴ The factors  of $84-2x-2x^2$ are (x-6) and (x+7).

Hence, the factors of  $84-2x-2x^2$ are (x-6) and (x+7).