We can get the answer to this equation by solving for the variable (r).
7.4 - 9 - 2r = 18
We want to get r on one side, so we want to push everything else to the other side.
-2r = 18 - 7.4 + 9
-2r = 19.6
2r = -19.6
r = -9.8
In this question, we have to write the set of points from -6 to 3 but excluding -2 and 3 as a union of intervals .
For union, we use U.
For the points that we have to exclude , we put parenthesis on there side that is ().
Therefore the required interval form is

As we see that () are used with -2 and 3 . And that's the required interval form .
X= 1st integer
x+2= 2nd integer
x+4= 3rd integer
Add the integers together
x + (x + 2) + (x + 4)= 279
combine like terms
3x + 6= 279
subtract 6 from both sides
3x= 273
divide both sides by 3
x= 91 first integer
Substitute x=91 to find 2nd & 3rd integers
2nd Integer
=x+2
=91+2
=93
3rd Integer
=x+4
=91+4
=95
ANSWER: The three test scores are 91, 93 and 95.
Hope this helps! :)