Question

How do you evaluate `\frac { 2} { 7} + ( - \frac { 1} { 2} )`?

Answer 1

`= - 3/14`

Explanation:

`\frac { 2} { 7} + ( - \frac { 1} { 2} )`

Remove the bracket:

`= \frac { 2} { 7} - \frac { 1} { 2}`

Create a common denominator:

`= \frac { 2} { 7} * underbrace(2/2)_(=1) - \frac { 1} { 2} * underbrace(7/7)_(= 1)`

`=4/14 - 7 /14`

`= - 3/14`

Answer 2

`-3/14`

Explanation:

When we add or subtract fractions, we need a common denominator. Let's get our denominator to be `14`.

We can do this by multiplying `2/7` by `2/2`, and `-1/2` by `7/7`. Notice, we're multiplying by `1`, so we didn't change the value of this expression.

We now have

`4/14-7/14=-3/14`

Hope this helps!