Ok so we'll go ahead and solve for y first - we just need to get it alone on one side of the equal sign
Step 1: subtract 2x from each side
2x - 7y - 2x = 19 - 2x
This cancels out the 2x on the left, giving us
-7y = 19 - 2x
Step 2: divide both sides by -7
= 
+ 
This gives us
y = -19/7 + 2x/7
That should be your answer for the first question. Now solving the next parts are easy. All you need to do is plug in x.
When x = -3
y = -19/7 + 2x/7
y = -19/7 + 2(-3)/7
y = -19/7 - 6/7
y = -25/7
When x = 0
y = -19/7 + 2x/7
y = -19/7 + 2(0)/7
y = -19/7
When x = 3
y = -19/7 + 2x/7
y = -19/7 + 2(3)/7
y = -19/7 + 6/7
y = -13/7
Hope that helps! Feel free to ask if I can help with anything else :)
When you see questions of this nature, test the individual inequalities and look out for their intersection.
For
Choose a point in the lower or upper half plane created by the line
The above line is the one which goes through the origin.
Now testing (1,0) yields,
That is,
This statement is true. So we shade the lower half of
For
We test for the origin because, it is not passing through the origin.
This yields
This statement is false so we shade the upper half.
The intersection is the region shaded in B. The top right graph
Let
where we assume |r| < 1. Multiplying on both sides by r gives
and subtracting this from 
gives
As n → ∞, the exponential term will converge to 0, and the partial sums will converge to
Now, we're given
We must have |r| < 1 since both sums converge, so
Solving for r by substitution, we have
Recalling the difference of squares identity, we have
We've already confirmed r ≠ 1, so we can simplify this to
It follows that
and so the sum we want is
which doesn't appear to be either of the given answer choices. Are you sure there isn't a typo somewhere?
You would start out by putting 225 over 100 then simplifying from there. You would end up getting 9/4. As a mixed number that would be 2 and 1/4.
