Answer:
x = -1
y = -1
Explanation:
This is a system of equations- the set up of the problem lends well to using the elimination method. There are always many ways of solving a system of equations, both in methods and different strategies within each method. The problem isn't necessarily complete but I can assume you're being asked to solve for x and y values.
divide the first equation by -2. this means we can use elimination to cancel out the y value, and is also our simplest option (rather than multiplying the second equation by -2.
-2x + 20y = -18 --> x - 10y = 9
x - 10y = 9
8x + 10y = -18
Using the elimination method to essentially add the parts of the equations together, this comes out to 9x = -9 , meaning x = -1 .
We can then return to our original equations, and substitute -1 for x (either equation will work, but the second one is simpler and therefore the better option).
8 (-1) +10y = -18
-8 + 10y = -18
10y = -10
y = -1
CHECKING
Substitute both x and y values back into the original equations to check them. the sides should be equal if our values are correct.
-2 (-1) + 20 (-1) = -18
Our first equation works: 2 - 20 = -18
8 (-1) + 10 (-1) = -18
The second equation works as well: -8-10= -18