Math, asked by sharmanickankupe4hxy, 1 year ago

x=2÷3 and x= -3 are roots of quadratic equation ax²+7x+b=0 find the vaues of a and b

Answers

Answered by TheLostMonk
2
given roots ,

x = 2 / 3 , x = - 3

given equation,

ax^2 + 7x + b = 0 ---eq.(1)

put, x = 2 / 3 in (1)

a ( 2/ 3 )^2 + 7 (2/3) + b = 0

4a / 9 + b = - 14 / 3 ---------------eq.( 2 )

put x = - 3 in (1)

a(-3 )^2 + 7(-3) + b =0

9a +b = 21 ---------(3)

subtract eq.(2) from eq. (3)

9a - 4a / 9 = 21 + 14 / 3

77a / 9 = 77 / 3

a =77 ×9 / 3×77

a = 9 / 3 = 3

a = 3

put value of a in eq. (3) ,we get,

b = 21 - 27

b = - 6

hence, a = 3 and b = - 6

◆hope it helps ◆
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