Question

construct pair of equation if sum of two number is 30 and their difference is 10

Answer 1

Let x be the smaller number
so,,x+(x+30 )=( x+30)- 10

Answer 2

x+y=30
x-y=10

$x + y = 30 \\ x - y = 10 \\ = )2x = 40 \\ = )x = 20 \\ putting \: the \: value \: of \: x \: we \: got \\ = )y = 10$