Question

X+2y+z=7; x+3z=11; 2x+3y=1

Answer 1

Hi friend,

Substitution method:-

x+2y+z = 7

x+3z = 11

2x-3y = 1

→ x+3z = 11

x = 11-3z

→ 2x-3y = 1

2(11-3z) = 1+3y

22-6z = 1+3y

3y = 21-6z

y = 3(7-2z)/3

y = 7-2z

Substitute x and y values,

x+2y+z = 7

11-3z+2{7-2z}+z = 7

11-3z+14-4z+z = 7

25-6z = 7

6z = 25-7

6z = 18

z = 18/6 = 3

x = 11-3z = 11-3(3) = 11-9 = 2

y = 7-2z = 7-2(3) = 7-6 = 1

Therefore, x = 2 , y = 1 and z = 3

Hope it helps......