Question

solve b from the given question

Answer 1

it is given that (x+1) is a factor of given equation
so it will satisfy the equation.on finding value of x.
x,=-1
putting this value in equation
(-1)3+9(-1)2-a+15=0
-1+9-a+15=0
a=23
Hope it will help you

Answer 2

HELLO!!!
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x+1 is a factor of x^3+9x^2+ax+15
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x = -1
So,
➡️x^3+9x^2+ax+15 =0
(-1)^3 + 9(-1)^2+a(-1)+15 = 0
-1 + 9 - a + 15 = 0
8+ 15 - a = 0
23 - a = 0
- a = -23
a = 23
So , The value of a is 23✔✔
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HOPE IT HELPS U✌✌