Question 143784
subtracting z from 2nd equation __ y=6-z


adding z to 3rd equation __ x=7+z


substituting into 1st equation __ 2(7+z)+(6-z)=17 __ distributing __ 14+2z+6-z=17


20+z=17 __ subtracting 20 __ z=-3


substituting __ y+(-3)=6 __ adding 3 __ y=9


substituting __ x-(-3)=7 __ adding -3 __ x=4