if -5 is the root of quadratic equation 2 x square + px - 15 equal to zero and quadratic equation p(x square + x )+ k equal to zero has equal roots then find the value of k
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x = -5
so , 2(-5)²+p(-5)-15=0
50 -5p - 15=0
5p= 35
so, p = 7
Now p(x²+x)+k=0
px²+px+k=0
7(-5)² +7(-5)+k =0
7×25- 35+k =0
175 - 35 + k =0
140+k = 0
k = -140. (ans)
so , 2(-5)²+p(-5)-15=0
50 -5p - 15=0
5p= 35
so, p = 7
Now p(x²+x)+k=0
px²+px+k=0
7(-5)² +7(-5)+k =0
7×25- 35+k =0
175 - 35 + k =0
140+k = 0
k = -140. (ans)
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