Hope this is what you are looking for
Step-by-step explanation:
Let's call x the lenght and y the height. The perimeter will be:
p = 2x + 2y = 10
When the lenght is halved and the height double we'll have:
p = x + 4y = 14
These 2 equations form a system of equations2 that can be solved and give as result:
y = 3
x = 2
The solution to the equation would be 21.5
Why?
If you do the equation backwards
30 - 8.5 = x
You would get 21.5
You can plug it into the first equation to check!
:)
