please help me in this question
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VaibhavPrasad:
this is class 10?
yes
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x=-4 is a root of x2+2x+4p=0
putting x=-4
(-4)2+2(-4)+4p=0
16-8+4p=0
hence,p=-2
according to question,
x2+px(1+3k)+7(3+2k) has equal roots
therefore,
{p(1+3k)}2-4{7(3+2k)}=0
{-2(1+3k)}2-84-56k=0
4(1+6k+9k2)-84-56k=0
4+24k+36k2-84-56k=0
36k2-32k-80=0
9k2-8k-20=0
9k2-18k+10k-20=0
9k(k-2)+10(k-2)=0
(k-2)(9k+10)=0
Hence,k=2 or -10/9 hope it will help you.
putting x=-4
(-4)2+2(-4)+4p=0
16-8+4p=0
hence,p=-2
according to question,
x2+px(1+3k)+7(3+2k) has equal roots
therefore,
{p(1+3k)}2-4{7(3+2k)}=0
{-2(1+3k)}2-84-56k=0
4(1+6k+9k2)-84-56k=0
4+24k+36k2-84-56k=0
36k2-32k-80=0
9k2-8k-20=0
9k2-18k+10k-20=0
9k(k-2)+10(k-2)=0
(k-2)(9k+10)=0
Hence,k=2 or -10/9 hope it will help you.
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