rearrange the first equation so it matches the second equation and then use elimination method to solve. Or substitute 2x-5 for y into the second equation and solve. You will end up with one of the following:
--> x = some value and y = some value (ONE SOLUTION)
--> A True statement, such as 0 = 0, or 1=1, etc (INFINITELY MANY SOLN'S)
--> A False statement, such as 0 = 1, or 5 = 7, etc (NO SOLUTIONS)
Using substitution method:
-8x - 4(2x - 5) = -20
-8x - 8x + 20 = -20
-16x = -40
x = -40/16
Answer: One Solution