In order for the triangle to be isosceles, we have to set two lengths of the triangle equal to each other.
Let's take the lengths 5x-12 and x+20 and set them equal to each other.
5x - 12 = x + 20
Combine like terms by moving them over to their respective sides.
Subtract x from both sides of the equation.
4x - 12 = 20
Add 12 to both sides of the equation.
4x = 32
Divide both sides by 4.
x = 8
Check your answer by substituting.
5x - 12 = x + 20
5(8) - 12 = 8 + 20
40 - 12 = 28
28 = 28
Solution: x = 8
This is a geometric progression problem. We can the general formula that can tell us how many flowers would be planted each month.
Let's write the terms that we know and see if we can find the pattern:

The patern here is obvious. Let's write it down:

This formula gives us a number of flowers planted in the n-th month.
Answer:
Is there a graph that goes with this question by chance?
Step-by-step explanation:
N(3)-8=16
add 8 to both sides
3n=24
Divide each side by three
n=8
The mean can be found by adding the two numbers and dividing by 2
let the second number be y
(x + y)/2 = 1/2x + 1
solve for y
multiply each side by 2
x + y = 2(1/2x + 1)
distribute
x + y = x + 2
subtract x on both sides
y = 2
ANSWER: the second number is 2