Question

x²-3x-2=0 Solve using formula.

Answer 1

Hi ,

compare x² - 3x - 2 = 0 with ax²+bx+c= 0

we get

a = 1 , b = -3 , c = -2

discreaminant ( D ) = b² - 4ac

D = ( -3 )² - 4 × 1 × ( -2 )

D = 9 + 8

D = 17

By Quadratic formula ,

x = [ ( - b ± √D )/2a ]

x = [ ( -(-3 ) ± √17 ) ]/( 2 × 1 )

x = ( 3 ± √17 )/2

Therefore ,

x = ( 3 +√17 )/2 or x = ( 3 - √17 )/2

I hope this helps you.

: )

Answer 2

Answer:

in factorization method

Given x 2−3x+2=0

x 2−2x−1x+2=0 (Resolving the expression)

x(x−2)−1(x−2)=0 (Taking common factors)

(x−2)(x−1)=0 (Taking common factors)

∴x−2=0 or x−1=0 (Equating each factor to zero)

∴x=2 or x=1

∴2 and 1 are the roots of x 2−3x+2=0

Step-by-step explanation:

in formula method

a= 1 b= -3 c= -2

x = -b +- under root b²- 4ac /2 a

x = -(-3)+- under root (-3)-4(1)(-2)/ 2(1)

x = 3+- under root -9- (-8) /2

x = 3+- under root -9+8 /2

x= 3+- under root -1 /2

3+1/2 , 3-1/2

4/2 2/2

x= 2 x=1