Solve system of 3 linear equations in 3 variables by addition method..Please help?

Question

Please Help me, I have two probems I Just can NOT get

3x + 2y - 3z =8
2x +3y + 2z =10
x + y - z =2

Answer 1

3x + 2y - 3z = 8 (1)
2x + 3y + 2z = 10 (2)
x + y - z = 2 (3)

(1) - 3*(3) => y = -2.
(2) + 2*(3) => 4x + 5y =14 => x = 6
Finally from (3) => z = 2.

Answer 2

[a million] Eqn1 - 2eqn3 : -4x+5y=3 , eqn2 - 3eqn3 : -8x+12y=4 , multily the 1st eqn via 2 & subtract the 2nd eqn : -2y=2 , y=-a million , -4x+5(-a million)=3 , x=-2 , 3(-2)-2(-a million)+z=0 , z=4 . [2] j+b+c=1480 , j=one hundred twenty+b then one hundred twenty+b+b+c=1480 , 2b+c=1360 & b+c=j+280 , j+j+280=1480 , j=six hundred , b+c=880 , b=480 , c=4 hundred