7y=-24
y= -24/7
You have to add the two vaiables and then divide to get the y by itself.
13+4x=1-x
4x=-12-x (minus 13 from each side)
5x=-12 (add x to each side)
You divide -12 by 5x
-12÷5x=2

⇒2.4
x=2.4
Answer:
Diameter 16, radius 7, circumference 37.68, diameter 8
Step-by-step explanation:
Largest area will be in a circle with the largest radius. So let's find all radii.
d = 8, so r = 4;
r = 7;
circumference = 2pi*r = 37. 68, so r = 6
diameter 18, so r = 8