Question

Twice the sum of -2 and a number is the same as the number decreased by 7/8 find the number

Answer 1

We will have that the expression is:

`2(n-2)=n-(7)/(8)`

Now, we operate:

`\Rightarrow2n-4=n-(7)/(8)\Rightarrow n=-(7)/(8)+4`
`\Rightarrow n=(25)/(8)\Rightarrow n=3.125`

So, the number is 3.125.

***Explanation***

We are told that twice the sum of -2 and a number equals something, now, the sum of a number [That we are going to call "n"] and -2 is the following:

`n-2`

[Remember that when we add a number and a negative number we will write the negative value in the sum, subtraction is the sum of a negative number]. Now, we are told that is twice that number, so it is then:

`2(n-2)`

We are also told that that expression is equal to the number "n" decrease by 7/8, that is:

`n-(7)/(8)`

Finally, we equal both expressions and obtain the value that is described in the text:

`2(n-2)=n-(7)/(8)`

And to determine the value of "n" we simply operate like terms and leave "n" alone on one side.