Question

3. Which of the following equations has 2 as a root?
(a) x² - 4x + 5 = 0
(b) x² + 3x - 12 = 0
(c) 2x - 7x + 6 = 0
(d) 3x² - 6x - 2 = 0

pls do answer this seriously ,i need explanations too,i have exams tomorrow ​

Answer 1

u can easily find it by the discriminant formulae

i.e D=b^2-4ac

so if

D<0,then the equation has no real roots

D=0,then the equation has 2 real and equal roots

D>0,then the equation has 2 real and distinct roots

here,

a,b and c are the coffecients of x^2,x and the third no. is c

i could have answered ur question directly but i hope that if i have given you the concept,now you can solve and practice on your own