The sum of three numbers is 2. If twice the second number is added to the sum of first and third, we get 1. On adding the sum of second and third numbers to five times the first, we get 6. Find the three numbers by using matrices.

Question

Philoid · Accepted Answer

Let the three numbers be x, y and z.

According to the question,

X + y + z = 2

X + 2y + z = 1

5x + y + z = 6

Converting the following equations in matrix form,

AX = B

R₂ – R₁

R₃ – R₁

Converting back into the equations we get

X + y + z = 2

Y = - 1

4x = 5

X =

– 1 + z = 2

Z = 2 - + 1

Z =

∴ The numbers are .