Answer:
t =

Explanation:
calculate the gradient (slope) of AB using the slope formula and equate to the slope of the perpendicular line.
given line with slope 1
=

given a line with slope m then the slope of a line perpendicular to it is
= -
= -
= -

calculate
using slope formula
m =

with (x₁, y₁ ) = A (2, - 3 ) and (x₂, y₂ ) = B (- 2, t )
=
=

equating corresponding slopes
= -
( multiply both sides by - 4 to clear the fraction )
t + 3 = -
× - 4 =
( subtract 3 from both sides )
t =
- 3 =
-
=
