If -5 is a root of the quadratic equation 2x2+px-15=0 and quadratic equation p (×2+×)+k=0 has equal roots find the value of k
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Since -5 is a root of the equation 2x²+px-15=0 & p(x²+x)+k=0
x=-5
2(-5)²+p(-5)-15=0
50-5p-15=0
35=5p
:.p=7
p(x²+x)+k=0
7{(-5)²+(-5)}+k=0
7(25-5)+k=0
7(20)+k=0
140+k=0
k=-140
x=-5
2(-5)²+p(-5)-15=0
50-5p-15=0
35=5p
:.p=7
p(x²+x)+k=0
7{(-5)²+(-5)}+k=0
7(25-5)+k=0
7(20)+k=0
140+k=0
k=-140
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