Question

If x=2/3and x= -3 are the root of a quadratic equation X^2+ 7 x + b is equal to zero then find the value of a and b

Answer 1

x=2/3.. x= -3
Put value of x in quadratic equation

X^2 + 7x + b = 0
(-3)^2 + 7(-3) + b = 0
9 - 21 + b = 0
-12 +b = 0
b = 12..
[HOPE IT'S HELP U]
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Answer 2

Hii friend,

X = 2/3

PUTTING THE VALUE OF X IN EQUATION,

aX²+7X+b = 0

a×(2/3)²+ 7×2/3 + b = 0

a×4/9+14/3+b = 0

4a+42+9b/9 = 0

4a+42+9b = 0

4a+9b = -42

9b = -42-4a

b = -42-4a/9.......(1)

Again,

X = -3

PUTTING THE VALUE OF X IN EQUATION,

aX²+7X+b = 0

a×(-3)²+7×-3+b= 0

9a -21+b = 0

9a+b = 21

PUTTING THE VALUE OF B IN EQUATION,

9a+b = 21

9a+ (-42-4a/9) = 0

SOLVE THIS U WILL GET THE VALUE OF a. After finding the value of a put in equation (1). U WILL GET THE VALUE OF b..

HOPE YOU WILL UNDERSTAND THIS..