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The Sum of Four Times the First Number and Three Times the Second Number is 15. the Difference of Three Times the First Number and Twice the Second Number is 7. Find the Numbers. - Mathematics

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प्रश्न

The sum of four times the first number and three times the second number is 15. The difference of three times the first number and twice the second number is 7. Find the numbers.

योग
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उत्तर

Let the two numbers be x and y respectively.
Then, we have
4x + 3y = 15    ....(i)
3x - 2y = 7      ....(ii)
Multiplying eqn. (i) by 2 and eqn. (ii) by 3, we get
8x + 6y = 30  ....(iii)
9x - 6y = 21   ....(iv)
Adding eqns. (iii) and (iv), we get
17x = 51
⇒ x = 3
⇒ 4(3) + 3y = 15
⇒ 12 + 3y = 15
⇒ 3y = 3
⇒ y = 1
Thus, the two numbers are 3 and 1 respectively.

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Methods of Solving Simultaneous Linear Equations by Elimination Method
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अध्याय 8: Simultaneous Linear Equations - Exercise 8.3

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फ्रैंक Mathematics [English] Class 9 ICSE
अध्याय 8 Simultaneous Linear Equations
Exercise 8.3 | Q 4

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