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Question
If x=2 and x=−3 are roots of the quadratic equation ax2+7x+b=0, find the values of a and b.
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Solution
Given x=2 & x=−3are roots of quadratic equationax2+7x+b=0 ....(1)
for x=−24a+14+b=04a+b=−14 ....(2)
For x=−39q−21+b=09a+b=21....(3)
On subtraction eq (2) & (3) we get
4a+b=−149a+b=21=>−5a=−35[a=7] & b=21−63=−42[b=−42]
Given x=2 & x=−3
are roots of quadratic equation
ax2+7x+b=0 ....(1)
for x=−2
4a+14+b=0
4a+b=−14 ....(2)
For x=−3
9q−21+b=0
9a+b=21....(3)
On subtraction eq (2) & (3) we get
4a+b=−14
9a+b=21
=>−5a=−35
[a=7] & b=21−63=−42
[b=−42]
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