We will solve by elimination as follows:
-3x - 8y = 20 [We multiply one of the equations by a number so we obtain an equal value in one of them]
8(-5x + y = 19)
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-3x - 8y = 20
-40x + 8y = 152
------------------------- [We now add both expressions and solve for the resulting equation]
-43x = 172 => x = -4
Now that we know the value of one of the variables we replace this in one of the first equations:
=> -3(-4) - 8y = 20 => 12 -8y = 20=>-8y = 8 => y = -1
So, from this, we have that the solution for the system is (-4, -1)