4x + y = 2
x - y = 3
you can use any method and show how to get to the answer so i understand in the future

Cancel by elimination 
4x+y=2
x-y=3
5x=5 because the Ys cancel out because it is positive and negative
x=1 when you divide by 5 on both sides to find x
then plug 1 in for x in a equation then solve
4(1)+y=2
4+y=2
y=-2 when you subtract 4 on both sides 
(1,-2)

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!