-6
You would divide -4.3 on both sides. Since -4.3 divided by itself equals 1 the g will be isolated. So the answer would be -6 because 25.8 divided by -4.3 is -6.
Check the picture below
notice, if the "r" and "h" is the same for both, the cone's volume is just 1/3 of the cylinder's
Yes it is a rational number