Question

which of following is a root of x²-7x+12= 0. a)4 b)-4 c)-5 d)5​

Answer 1

Answer:

The answer is a)4

Step-by-step explanation:

Given the equation is x²-7x+12=0

⇒x²-(4x+3x)+12=0

⇒x²-4x-3x+12=0

⇒x(x-4)-3(x-4)=0

⇒(x-4)(x-3)=0

∴x= 4, 3

Therefore the root is a) 4

Answer 2

Answer:

The correct option is a) 4

Step-by-step explanation:

As we have been mentioned above that the polynomial is $x^{2} - 7x + 12 = 0$

For finding its roots we have to first mid-term factorize or split the respective polynomial and then we will find its roots. We have it as below:

$x^{2} - 7x + 12 = 0$

⇒ $x^{2} - ( 3+4)x + 12 = 0$

⇒ $x^{2} - 3x - 4x + 12 = 0$

⇒ $x ( x -3) -4 (x -3) = 0$

⇒ $(x-4)(x-3)=0$

⇒ x = 4,3

Hence among the following given options, a) 4 is correct.