I would subtract the 2nd from the first one
so -4x - -2x = -2x
4y - 4y = 0
-20 - -2 = -18
-2x = -18
now I would divide that by -2 to get the value for x
so no we have x = 9
now you just have to substitute that into one of the equations and simplify to get y
-2 X 9 + 4y = -2
-18 + 4y = -2
4y =16
y = 4
The answer of the question which you asked above is
36^6x-6^5x=1
1. Perimeter
22a + 2(6a + 8) -4 = p
[I got 22a from 12a + 10a]
2. If p = 250, what is a?
22a + 2(6a + 8) - 4 = 250
Distributive property
22a + 12a + 16 - 4 = 250
Add like terms
34a + 12 = 250
Subtract 12 by both sides
34a = 238
Divide 34 by both sides
a = 7