Question

(it). *(x + 1) + 8 = (x+2)(x-2)​

Answer 1

$\sf\huge\bold{\underline{\underline{{Solution}}}}$

=>(x+1)+8= (x+2)(x-2)

Identity used here :

(a+b)(a-b)=a²-b²

=>x+9=x²-4

=>x²-x-4-9=0

=>x²-x-13=0

It is in the form of a quadratic equation so we,use quadratic formula for finding the roots.

Quadratic formula:

x= -b±√b²-4ac / 2a

by using quadratic formula:

a= 1 ,b= -1 & c= -13

=>x= -(-1)±√(-1)²-4(1)(-13) / 2(1)

=>x= 1±√1-(-52) / 2

=>x= 1±√53 / 2

Here,the discriminant b²-4ac is >0

So, there are two real roots.

=>x= 1±√53 / 2

Write separate term :

=>x= 1/2 ± √53/2

x= 4.14005

x= -3.14005