Final answer:
The expression 3x 4 can be written as 'the sum of three times a number and four' or 3x + 4.
Step-by-step explanation:
The expression 3x 4 can be written as 'the sum of three times a number and four'. In this expression, '3 times a number' represents the product of 3 and a variable, and 'four' represents a constant value. The sum of these two terms gives us 3x + 4.