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# If Two Zeros X3 + X2 − 5x − 5 Are √ 5 and − √ 5 , Then Its Third Zero is - Mathematics

MCQ

If two zeros x3 + x2 − 5x − 5 are $\sqrt{5}\ \text{and} - \sqrt{5}$, then its third zero is

#### Options

•  1

• −1

• 2

• −2

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#### Solution

Let alpha = sqrt5 and beta= -sqrt5 be the given zeros and y  be the third zero of x3 + x2 − 5x − 5 = 0 then

By using alpha +beta + y = (-text{coefficient of }x^2)/(text{coefficient of } x^3)

alpha + beta + y = (+(+1))/1

alpha + beta + y = -1

By substituting alpha = sqrt5 and beta= -sqrt5 in alpha +beta+y = -1

cancel(sqrt5) - cancel(sqrt5) + y = -1

 y = -1

Hence, the correct choice is(b)

Is there an error in this question or solution?
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#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 2 Polynomials
Q 22 | Page 63
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