Question

if (x+1) is factor of (Xcube + a) then write the value of a​

Answer 1

a=1

(x+1)=0

x= -1

now put the value of x in equation

x^3+a=0

(-1) + a=0

-1= -a

a =1

so value of a is 1

Answer 2

$Let \: p(x) = x^{3} + a$

$Given \: (x+1) \:is \: a \: factor \: p(x)$

$\pink { ( By \: Factor \: theorem ) }$

$\blue { p(-1) = 0 }$

$\implies (-1)^{3} + a = 0$

$\implies -1 + a = 0$

$\implies a = 1$

Therefore.,

$\red{ Value \:of \: a } \green {= 1 }$

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