Question

Eight times the sum of a number and 9 equals 3. Use the variable c for the unknown number.

Answer 1

8(c + 9) = 3

Explanation:

Our task is to find the number.

We're given an equation that's described in words:

"Eight times the sum of a number and 9 equals 3."

The number is c. So now, what is the sum of 9 and c? Well, we all know that the sum of x and y is x + y. By the same analogy, the sum of 9 and c is 9 + c.

Now, if we multiply 8 times a sum, we put the sum in parentheses.

We end up with this equation:

`8(c+9)=3`

`\hspace{370}\above4`

(Optional) Solve for c.

`8(c+9)=3`

`8*c+8*9=3`

`8c+72=3`

`8c=3-72`

`8c=-69`

`c=-(69)/(8)`

Answer 2

`8(c + 9) = 3`

`c + 9 = (3)/(8)`

`c = - (78)/(8) = - (39)/(4) = - 9 (3)/(4)`