Question

j Perform multiplication of following algebraic expressions using appropriate

identities.

1. (x+7 )(x-1)​

Answer 1

Answer:

$(x+7 )(x-1)=x^{2} +6x-7$

Step-by-step explanation:

We know the identity,

                         $(x+a)(x+b)=x^{2} +(a+b)x+ab$

Comparing (x+7 )(x-1)​ with $(x+7 )(x-1)$

             a=7 and b=-1

                       $(x+7 )(x-1)\\ \\ =x^{2} +(7-1)+(7)(-1)\\ \\ =x^{2} +6x-7$

Answer 2

Answer:

x² - x + 7x - 7

= x² + 6x - 7