Question

guys please help I need urgently I definitely make the brain list,but please make sure that I need to get the complete process​

Answer 1

Answer:

x = -2, 4

Step-by-step explanation:

Given,

(x+3)•(x-5) = -7

On further solving, we get,

=> x^2 - 5x + 3x - 15 = -7

=> x^2 - 5x + 3x - 15 + 7 = 0

=> x^2 - 2x - 8 = 0

For the values of x, by using splitting the middle term,

=> x^2 - 4x + 2x - 8 = 0

=> x(x - 4) + 2(x - 4) = 0

=> (x + 2)(x - 4) = 0

For the values of x,

CASE I :

(x + 2) = 0

=> x = -2

CASE II :

(x - 4) = 0

=> x = 4

Hence, values of

x = -2, 4

Answer 2

Question :

Solve the following, ( x + 3 )( x - 5 ) by factorisation method.

AnsWer :

x = -2 and 4.

Solution :

We have, Equation.

→ ( x + 3 )( x - 5 ) = - 7.

→ ( x² - 5x + 3x - 15 ) = - 7.

→ x² - 2x - 15 = - 7.

→ x² - 2x = - 7 + 15.

→ x² - 2x = 8

→ x² - 2x - 8 = 0.

★ Let's Factories the middle term ( Splitting the middle term )

→ x² - 2x - 8 = 0.

→ x² - 4x + 2x - 8 = 0.

→ x( x - 4 ) + 2( x - 4 ) = 0.

→ ( x - 4 )( x + 2 ) = 0.

$\rule{90}1$

Either,

→ x - 4 = 0.

→ x = 4.

$\rule{90}1$

Or,

→ x + 2 = 0.

→ x = - 2.

$\rule{200}3$

★ Let's try With Some other method ( Quadratic Formula )

$\tt\dagger \: \: \: \: \: x = \dfrac{ - b \pm \sqrt{ {b}^{2} - 4ac} }{2a}$

Where as,

• a = 1.
• b = - 2.
• c = - 8.

$\tt : \implies x = \dfrac{ 2 \pm \sqrt{ {( - 2)}^{2} - 4 \times 1 \times - 8} }{2}$

$\tt : \implies x = \dfrac{ 2\pm \sqrt{ 4 + 32} }{2}$

$\tt : \implies x = \dfrac{ 2\pm \sqrt{ 36} }{2}$

$\tt : \implies x = \dfrac{ 2\pm 6 }{2}$

Either,

$\tt : \implies x = \dfrac{ 2 + 6 }{2}$

$\tt : \implies x = \dfrac{ 8}{2}$

$\tt : \implies x = 4.$

Or,

$\tt : \implies x = \dfrac{ 2 - 6 }{2}$

$\tt : \implies x = \dfrac{ - 4}{2}$

$\tt : \implies x = - 2.$

Therefore, the value of x is - 2 and 4.