The Sum Of Two Numbers Is 30 And Their Difference Is 10

The problem given says that 2 unknown numbers are given, whose sum is equal to 30 and the difference is 10. Let's find the two numbers :

When we add the two numbers :
X + Y = 30

The difference of two numbers :
X - Y = 10

Solution :

If we add the two equations eachother , then we can find the first number.

X + Y = 30
X - Y = 10

2X = 40

Let's divide 40 to 2 for the first number "X" .

X/2 = 20

First number is 20

X + Y = 30
So ;
20 + Y = 30
Y = 30 - 20
Y = 10

Second number is 10

Question & Answer
The Sum Of Two Numbers Is 30 And Their Difference Is 10 : 20 And 10