What point is 5 units left and 2 units down from (1,2)?

When keisha installed a fence along the 200 foot perimeter of her rectangular back yard, she left an opening for a gate.in the diagram below, she used x to represent the length in feet of the gate? what is the value? a. 10 b. 20 c. 25 d. 30

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18