7−5z=17+5z 
Step 1: Simplify both sides of the equation. 
7−5z=17+5z 
7+−5z=17+5z 
−5z+7=5z+17 
Step 2: Subtract 5z from both sides. 
−5z+7−5z=5z+17−5z 
−10z+7=17 
Step 3: Subtract 7 from both sides. 
−10z+7−7=17−7 
−10z=10 
Step 4: Divide both sides by -10. 
−10z 
−10 
= 
10 
−10 
z=−1