There are three equations in this question, ①y=2x-7, ②5x+3y+2z=2, ③3x-4z=4. Transform equation ③ to get z=3/4x- 1④. Substitute Equations ① and ④ into Equation ② to get 5x+3(2x-7)+2(3/4x- 1)=2, and solve x=2. Substitute x=2 into equation ① and calculate y=-3. Then substitute x=2 into equation ④ to get z=0.5, so x=2, y=-3 and z=0.5.