the sums of two zeros of a polynomial p(x) is 3 and the third root is 7 p (x) = 3x³+bx²-cx+100 find the value of b
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Answer:
b = -30
Step-by-step explanation:
Let the zeroes of the polynomial p(x) be x, y and z.
p(x) = 3x³ + bx - cx + 100 = 0
= kx³ + lx² + mx + n = 0
where k = 3, l = b, m = -c, n = 100
We are given that,
x + y = 3 and z = 7
We know that, in a cubic equation,
Sum of zeroes = -(l)/k
= x + y + z = -(b)/3
= (x + y) + z = -b/3
= 3 + 7 = -b/3
= 10 = -b/3
-b = 30
b = -30
Hope it helped and you understood it........All the best
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