I can't speak to the cactus specifically, but any sphere has a surface area of

and a volume of

, so the area-to-volume ratio wold be


Where <em>r</em> is the radius of the sphere.
X=80°
A triangle’s angle measurements always add up to 180°. So 180-70-30=80
Given:
The equation is:

To find:
The error in the given equation and correct it.
Solution:
We have,

Taking left-hand side, we get

![[\because a^2-b^2=(a-b)(a+b)]](https://tex.z-dn.net/?f=%5B%5Cbecause%20a%5E2-b%5E2%3D%28a-b%29%28a%2Bb%29%5D)
![[\because (ab)^x=a^xb^x]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%28ab%29%5Ex%3Da%5Exb%5Ex%5D)

It is not equal to right-hand side
. In the right hand side, there must be a negative sign instead of positive sign.
Therefore,
.
So you have to decrease £30 by 20%
To do this, an easy way would be to first take away 100% from 20% because you are DECREASING :
100 - 20 = 80
Then divide your answer by 100 :
80 / 100 = 0.8
This means 0.8 is going to be your multiplier so you do
0.8 * 30 = 24
Answer = £24