4. \( \frac{z}{4}-3=6 \)
\( z = 36\)
Step 1 :\( \frac{z}{4} = 3 + 6\)
Step 2 :\( \frac{z}{4} = 9\)
Step 3 :\( z = 4 \times 9\)
Step 4 :\( z = 36\)