Question

If P(–1, 1) is the midpoint of the line segment joining A(–3, b) and B(1, b + 4) then b = ?

Options

• 1

• –1

• 2

• 0

Answer 1

–1

Explanation:

Midpoint y-coordinate gives `(b + (b + 4))/2 = 1`

⇒ `(2b + 4)/2 = 1`

⇒ b + 2 = 1

⇒ b = –1