Answer:
2. x=5
y=10
3. x=21
y=4
Explanation:
2. 13y=20x+3y 10y=20x
8x+y=180-13y 14y=180-8x
y=2x plugging that into 14y=180-8x 28x=180-8x 36x=180 x=5
plug x into 10y=20x 10y=100 y=10
3. 3(x+y)=(4x-9) 3x+3y=4x-9 x=3y+9
5x=180-4x+9 9x=189 x=21
plug 21 into x=3y+9 21=3y+9 12=3y 4=y