Let x be the amount of money Brian had in his account before he wrote the check. Brian spent $105, which we must subtract from the total. After the subtraction, we have $536 left, so the equation is
For the answer to the question above, since the triangle is isosceles, the two legs have equal length. The coordinates of two vertices are given
P(3,3)
Q(3,1)
Assuming that PQ and QR are the legs of equal length, the distance between Q and R must be the same as the distance between P and Q
d = √[(3-3)² + (3-1)²
d = 2
Therefore, the coordinates of P is
(5,1)