Question

translate the following phrase into an expression. the sum of three times a number x and -7. 3·x - 7 ×

Explanation:

Step1: Identify three - times a number x

Three times a number $x$ is written as $3x$.

Step2: Identify the sum with - 7

The sum of $3x$ and $-7$ is written as $3x+( - 7)$ or $3x - 7$. But the original answer missed the parentheses around the addition operation conceptually. The correct way to represent the sum of two terms is to consider them as separate entities being added. The correct expression for the sum of three times a number $x$ and $-7$ should be $3x+( - 7)=3x - 7$ where the intention of addition is clear. If we want to be more explicit in showing the sum operation, we can write it as $3x+( - 7)$.

Answer:

$3x+( - 7)$