## Precalculus (10th Edition)

We can verify the equations by substituting in the given $x$, $y$ and $z$ values and then check if the equalities still hold. Here: $4x-5z=4(4)-5(2)=16-10=6$, which is correct. $5y-z=5(-3)-2=-15-2=-17$, which is correct. $-x-6y+5z=-4-6(-3)+5(2)=-4+18+10=25$, which is correct.
We can verify the equations by substituting in the given $x$, $y$ and $z$ values and then check if the equalities still hold. Here: $4x-5z=4(4)-5(2)=16-10=6$, which is correct. $5y-z=5(-3)-2=-15-2=-17$, which is correct. $-x-6y+5z=-4-6(-3)+5(2)=-4+18+10=25$, which is correct.