Ranjit scores 80 marks in English and $x$ marks in Hindi. What is his total score in the two subjects?

Hint: The marks of Hindi is variable, so the total score will also be variable. The total score in the two subjects is given by the sum of marks scored in English and marks scored in Hindi. After that substitute, the marks scored in English and marks scored in Hindi. The sum will be the desired result.

Complete step by step answer:
Given: - Marks scored by Ranjit in English = 80
Marks scored by Ranjit in Hindi = $x$
To find: - Total score in the two subjects.
The total score in the two subjects is given by the sum of marks scored in English and marks scored in Hindi.
Total score in the two subjects = (Marks scored in English) + (Marks scored in Hindi)
Substitute the marks scored in English and marks scored in Hindi,
Total score in the two subjects = $80+x$

Hence, the total score in the two subjects is $\left( 80+x \right)$ marks.

Note:
The addition is one of the basic arithmetic operations in Mathematics. The addition is the process of adding things together. To add the numbers together, a sign “+” is used. The numbers which are going to add is called “addends” and the result which we are going to obtain is called “sum”. Addends can be any numbers such as positive integer, a negative integer, fractions, and so on.
There are four Maths properties defined for addition: -
Commutative Property
A + B = B + A
Associative Property
A + (B + C) = (A + B) + C
Distributive Property
A × (B + C) = A × B + A × C
Additive Identity
A + 0 = A = 0 + A