Answer:
2r² - 60r - 45 = 0
Step-by-step explanation:
Hang on this is going to be convoluted
------------------------------
Area of pond
a = πr²
Area of path
a = πr²/10
Combined Area
a = πr² + πr²/10
a = π(r² + r²/10)
---------------------------
The Combined Area can also be expressed as
a = π(r + 1.5)²
a = π(r² + 3r + 2.25)
-----------------------------
Set the areas equal
π(r² + r²/10) = π(r² + 3r + 2.25)
Divide both sides by π
r² + r²/10 = r² + 3r + 2.25
Subtract r² from both sides
r²/10 = 3r + 2.25
Multiply both sides by 20
2r² = 60r + 45
Subtract 60r + 45 from both sides
2r² - 60r - 45 = 0
