Question

If l = 2(w + 1), which of the following correctly gives w in terms of l?

Answer?

Answer 1

Simplify the equation and solve for w.

• l = 2(w + 1)
• => l = 2w + 2
• => l - 2 = 2w
• => l/2 - 2/2 = 2w/2
• => l/2 - 1 = w

The value of w is l/2 - 1 .

Answer 2

`w=\frac12I-1`

Or
`w=\frac12(I-2)`

(both are correct - just different ways of writing the equation)

Explanation:

`I = 2(w + 1)`

Expand the bracket:

`\implies I = 2w + 2`

Subtract 2 from both sides:

`\implies I - 2 = 2w + 2 - 2\\\\\implies I - 2 = 2w`

Divide both sides by 2:

`\implies (I-2)/(2)=(2w)/(2)`

`\implies w=\frac12I-1`