Concept If x∈R then we express it by writing x Ry and say that " x is related to y with relation R " Thus, (x,y)∈R⇔xRy Calculation: Given 2x+3y=20 The relation R can be written as R={(1,6),(4,4),(7,2)} There are 3 elements in the form (x,y) are there in R.