Question

8. The sum of three numbers is 6. Twice the third number when added to the first number gives 7.
On adding the sum of the second and the third numbers to thrice the first number, we get 12.
Find the numbers using matrix method.

Answer 1

ANSWER ⤵️

Numbers are  3 , 1 , 2  if sum of three numbers = 6 and 2 * 3rd + 1st = 7 , 2nd + 3rd + 3* 1st = 12

First  Number = x

Second number  = y

Third number = z

the sum of three numbers be 6

x + y + z = 6------(1)

twice the third number when added to first number gives 7

2z + x  = 7------(2)

on addition of sum of second and third number to thrice of first number we get 12

y + z + 3x  = 12---- (3)

(3) - (1)

=> 2x = 6

=> x = 3

Putting in eq 2

=> 2z + 3 = 7

=> 2z = 4

=> z = 2

3 + y + 2 = 6

=> y = 1

Numbers are  3 , 1 , 2

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