John and Jivanti Together Have 45 Marbles. Both of Them Lost 5 Marbles Each, and the Product of the Number of Marbles They Now Have is 128. Form the Quadratic Equation to Find How Many Marbles They Had to Start With, If John Had X Marbles. - Mathematics

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John and Jivanti together have 45 marbles. Both of them lost 5 marbles each, and the product of the number of marbles they now have is 128. Form the quadratic equation to find how many marbles they had to start with, if John had x marbles.

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Solution

Let the number of John's marbles be x.

Therefore, number of Jivanti's marble = 45 - x

After losing 5 marbles,

Number of John's marbles = x - 5

Number of Jivanti's marbles = 45 - x - 5 = 40 - x

It is given that the product of their marbles is 128.

∴ (x - 5)(40 - x) = 128

⇒ 40x - x2 – 200 + 5x = 128

⇒ 45x - x2 – 200 - 128 = 0

⇒ 45x - x2 - 328 = 0

⇒ -(x2 - 45 + 328) = 0

⇒ x2 - 45 + 328 = 0

∴ The required quadratic equation is x2 - 45 + 328 = 0

  Is there an error in this question or solution?
Chapter 4: Quadratic Equations - Exercise 4.2 [Page 8]

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RD Sharma Class 10 Maths
Chapter 4 Quadratic Equations
Exercise 4.2 | Q 2 | Page 8

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