Question

use the identity (x+a) (x+b) = x^2 + (a+b)x + ab to find the following :

b.) (7x+5) (7x-1)
mention steps​

Answer 1

Step-by-step explanation:

(7x + 5) (7x - 1)

(7x)^2 + (5-1)7x + 5x-1

(7x+5) (7x-1)

Answer 2

★ GivEn ThaT :-

• (7x + 5) (7x - 1)

★ To FinD :-

• The required equation
• Roots of the Equation

★ IdEntiTy tO Be UseD :-

$\large{\purple{\boxed{\sf{\orange{(x + a)(x + b) = {x}^{2} + (a + b)x + ab}}}}}$

★ SoLuTioN :-

$\large{\sf{(7x + 5)(7x - 1) }}$

$\sf{ = {(7x)}^{2} + (5 - 1)x \: + (5 \times ( - 1)) }$

$\sf{ = {49x}^{2} + 4x \: + ( - 5) }$

$\sf\pink{ = {49x}^{2} + 4x - 5}$

which is your required Equation!!

Also, the roots of this Equation will be

$\large\pink{\sf{x = \frac{ - 5}{7} \: and \: \frac{1}{7} }}$

which are the required roots!!