The equation is .
(Distribute 2)
(Multiply:
)
(Subtract:
)
Apply subtraction property of equality: Subtract 4 from each side.
\ (Apply additive inverse property:
)
(Apply additive identity property:
)
Apply subtraction property of equality: Subtract 10z from each side.
\ (Apply additive inverse property:
)
(Subtract:
)
Apply division property of equality: If a = b then .
(Divide each side by 2)
(Cancel common terms)
(Divide:
)
Check:
\To substitute in
.
(Substitute z = 0)
(Multiply:
)
(Add: 0 + 4 = 4 and 0 + 8 = 8)
(Multiply:
)
(Subtract:
)
The equality is true
The solution is .