cheak weather 7+3x is a factor of 3x³-7x
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Answered by
1
put 7+3x=0
x=-7/3 in
3x^3-7x=3 (-7/3)^3-7 (-7/3)
=-343/9+49/3
=(-343+147)/9
=-196/9
no
x=-7/3 in
3x^3-7x=3 (-7/3)^3-7 (-7/3)
=-343/9+49/3
=(-343+147)/9
=-196/9
no
Answered by
2
Heya
We can use the remainder theorem
If a is a factor of p(x) then p(a)=0
7+3x= 0
x = -7/3
p(x) = 3x³-7x
p(-7/3)= 3(-7/3)³- 7(-7/3)
= 3(-343/27) +49/3
= -343/9 + 49/3
= -343+147/9
= -196/9
As the remainder is not 0, 7+3x isn't a factor.
Hope it helps
We can use the remainder theorem
If a is a factor of p(x) then p(a)=0
7+3x= 0
x = -7/3
p(x) = 3x³-7x
p(-7/3)= 3(-7/3)³- 7(-7/3)
= 3(-343/27) +49/3
= -343/9 + 49/3
= -343+147/9
= -196/9
As the remainder is not 0, 7+3x isn't a factor.
Hope it helps
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