Solve the system of equation 3y+2z=12 andy-z=9

The two equations given are:

3y + 2z = 12

y - z = 9

Now let us take the second equation first and find the value of y in relation to z

y = 9 + z

Now we will put the value of y found from the second equation in the first equation.

3y + 2z = 12

3 (9 + z) + 2z = 12

27 + 3z + 2z = 12

5z = 12 - 27

5z = - 15

z = - (15/5)

= - 3

Now again we will put the value of z in the second equation for finding the value of y

y = 9 + z

= 9 - 3

= 6

So we find the value of "y" is 6 and that of "z" is - 3