The answers are
1. 18
2. 1 1/15
{ 3-y=2x
{ x+1/2y=3/2
{ -y=2x-3
{ 1/2y=3/2-x
{ y=-2x+3
{ y=3-2x
-2x+3=3-2x
(x,y) = (x,-2x+3)
Answer:
Step-by-step explanation:
(10x-4)/5=20
decimal is x= 10.4
-2x - 13 = -3x - 5
Step 1: Combine like terms
x's go with x's (-2x and -3x). To do this add 2x to both sides
(-2x + 2x) - 13 = (-3x + 2x) - 5
(0) - 13 = (-x) - 5
- 13 = -x - 5
normal numbers go with normal numbers ( -13 and -5). To do this add 5 to both sides
(- 13 + 5) = -x + (- 5 + 5)
-8 = -x + (0)
-8 = -x
Step 2: Isolate x by dividing -1 to both sides (this will take the negative sign away from the x)

8 = x
x= 8
Hope this helped!