The sum of 7 and 2 is 8

We can introduce a variable ( a letter representing an unknown ) to help us solve this question.

Let χ = "a number..."

We can rewrite the sentence in the following way:

7( χ + 2 ) = 8

To solve for χ , we can first distribute 7:

7 ∗ χ + 7∗(2) = 8

7χ + 14 = 8 ⇐ since 7 times 2 is 14

Let's get χ by itself first. We do so by subtracting 14 from both sides of the equation:

7χ + 14 - 14 = 8 - 14

7χ + 0 = -6 ⇐

7χ = -6 ⇐

The last number in our way is that 7. Let's divide both sides by 7 ( which is the same as multiplying both sides by 1 / 7 ) to figure out what χ is:

7χ ∗ ( 1 / 7 ) = -6 ∗ ( 1 / 7 )

χ ∗ ( 7 / 7 ) = - 6 / 7 ⇐

χ ∗ ( 1 ) = - 6 / 7 ⇐

χ = - 6 / 7

Therefore ( we can also use ∴ to represent the word "therefore" ) our number in question is  -6 / 7

Step-by-step explanation: