SOLUTION: If one of the quadratic equation px^+15x-14=0 is 2/3 find the value of p and other root

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Question 1077628: If one of the quadratic equation px^+15x-14=0 is 2/3 find the value of p and other root
Found 2 solutions by amfagge92, josgarithmetic:
Answer by amfagge92(93) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the other root be x
sum of the roots =
2/3+x=-15/p
solving
2p + 3xp=-45 as eqn (i)

product of the root=
2/3*x=-14/p as eqn (ii)
gives
xp=-21
put xp in eqn (i)
2p +3(-21)=-45
2p-63=-45
p=9

hence,the other root is -7/3 using x=%28-b-sqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29+

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
r, the other root

system%28%282%2F3%29r=-14%2Fp%2Cand%2C2%2F3%2Br=-15%2Fp%29

r=%28-14%2Fp%29%283%2F2%29

r=-21%2Fp

substitute.
2%2F3-21%2Fp=-15%2Fp
2%2F3=21%2Fp-15%2Fp
2%2F3=6%2Fp
p=%286%2A3%29%2F2
highlight%28p=9%29

-
substitute for p to find r.
r=-%2814%2F9%29%283%2F2%29
r=-14%2F%283%2A2%29

highlight%28r=-7%2F3%29