Question

ABCD is rectangle AD is 14 cm AB is is 30 cm CD is x+y and BC is x-y find x and y

Answer 1

Given that ABCD is a rectangle 

Which means the opposite sides will be equal.

Thus

14= x-y .... (1)
30= x+y .... (2) 

Solving eq (1) and (2) we get

2x= 44
x=22 cm

Then y= 8cm

Answer 2

opposite sides of a rectangle are equal

so,   x+y=30 -(1)
         x-y=14 -(2)

subtracting (2) from (1)

x+y-(x-y) = 30-14
2y = 16
y = 8-(3)

on putting (3) in (1) we get
x = 22