Question

The sum of 7 times a number and 9 is 5 . Use the variable c for the unknown number.

Answer 1

c - the number

The sum of 7 times a number and 9 is 5:

`7c+9=5` subtract 9 from both sides

`7c=-4` divide both sides by 7

`\boxed{c=-(4)/(7)}`