Replace the second equation y=3x+4 into the first one:
2(3x+4)+5x=30
Now solve for x:
6x+8+5x=30
11x=30-8
11x=22
x=22/11
x=2
Finally, replace x=2 into y=3x+4
y=3*2+4
y=6+4 = 10
So the anwer is x=2, y=10
It's the perimeter, you just have to add all the sides. so the answer is 24!
The answer is D. 12
To find this you would add (5x+16) and (9x-4) and set them equal to 180, because angles on a straight line add up to 180:
5x+16+9x-4 = 180
Then you would solve that for x, and would get x=12
Hope this helps!
