Question

20) Which of the following
equations has 2 as a root? *
O a) x2 - 4x +5 = 0
Ob) x2 + 3x - 12 = 0
O c) 2x2 - 7x + 6 = 0
O d) 3x2 - 6x - 2 =0
​

Answer 1

Answer:

ANSWER

Substituting x=2 in given equations

A:

x

2

+4x−5⇒(2

2

)+4×2−5⇒4+8−5=7

B:

x

2

+3x+12⇒(2

2

)+3×2+12⇒4+6+12=22

C:

2x

2

−7x+6⇒2(2

2

)−7×2+6⇒8−14+6=0

D:

3x

2

−6x+2⇒3(2

2

)−6×2+2⇒12−12+2=2

Then (C) equation has 2 as a root.