Let x_1=x , x_2=y and x_3=z
So, the equations are:
Let use eliminate z first. Add first two equations. That gives 5x+y=10
Multiply first equation by 2 and add it to the third equation.
Add it to x+2y+2z=11
So we get 5x=5
We had 5x+y=10
Here we plug x=1 and find y
In 2x-y-z=-3 we plug x=1 and y=5 and find z
Answer is given below (on video)
Determine whether the given problem is an equation or an expression. If it is an equation, then solve. If it is an expression, then simplify.