The equation is
(Subtract ‘z’ from each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Add 4y to each side)
(Apply commutative property of addition:
)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Add:
)
(Divide each side by 7)
(Cancel common terms) \ \
The value of .