Is v=8u+8 linear equation

Solve equation [1] for the variable u

[1] u = v

// Plug this in for variable u in equation [2]

[2] 8•(v ) - 4v = -32
[2] 4v = -32
// Solve equation [2] for the variable v

[2] 4v = - 32

[2] v = - 8
// By now we know this much :

u = v
v = -8
// Use the v value to solve for u

u = (-8) = -8
Solution : {u , v } = { -8,-8}

The answer is d 18ft