Question

Find the value of the greater root of x2 - 13x + 12 = 0.

A) -12
B) -1
C) 1
D) 12

Answer 1

B) -1


Hope this helps

Answer 2

Option D 12 is the answer.

Explanation:

Given is a quadratic equation as

`x^2-13x+12=0`

To find the roots we can factorise this

Since last term = 12, and middle term -13 we can split middle term as -12 and -1

`x^2-12x-x+12 =0\\x(x-12)-1(x-12)=0\\(x-12)(x-1)=0\\x=12: x=1`

We know that there are two roots as 12 and 1.

The bigger root is obviously 12.

Option D is the answer

Verify:

Substitute 12 in the equation and check

`12^2-13(12)+12=144-156+12=0`

Hence our answer is right.