Should be $265 multiple 250 by 0.06 and u get 15 then just add them together
To model half-life, use the formula

. Here,

is the amount remaining after a length of time

.

is the amount that you start with.

is the half-life. You plug in 50 for

, 10 for

, and 25 for

. You get

.
Perpendicular bisectors are segment that passes through the mid point of a triangle, while altitude is the perpendicular distance from the base to the opposite vertex.