Which of the following equations has `2` as a root?

Options

A. `x^(2)-4x+5=0`
B. `x^(2)+3x-12=0`
C. `2x^(2)-7x+6=0`
D. `3x^(2)-6x-2=0`

Answer

C

Explanation

(a) Substituting `x=2` in `x^(2)-4x+5` we get `(2)^(2)-4(2)+5`
`=4-8+5=1!=0`
So `x=2` is not a root of `x^(2)-4x+5=0`
(b) Substituting `x=2` in `x^(2)+3x-12` we get
`(2)^(2)+3(2)-12`
`=4+6-12=-2!=0`
So `x=2` is not a root of `x^(2)+3x-12=0`
(c) Substituting `x=2 `in `2x^(2)-7x+16` we get
`2(2)^(2)-7(2)+6=2(4)-14+6`
`=8-14+6=14+6`
`=8-14+6=14-14=0`
so `x=2` is root of the equation `2x^(2)-7x+6=0`
(d) Substituting `x=2` in `3x^(2)-6x-2` we get
`3(2)^(2)-6(2)-2`
`=12-12-2=-2!=0`
So `x=2` is not a root of `3x^(2)-6x-2=0`