-8y + 1 = -9y. solve for y.

y = -1

Step-by-step:

-8y + 1 = -9y

Subtract 1 from both sides
-8y = -9y-1

Add 9y to both sides to isolate y
y = -1

Simplifying
8y + -1 = 9y

Reorder the terms:
-1 + 8y = 9y

Solving
-1 + 8y = 9y

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-9y' to each side of the equation.
-1 + 8y + -9y = 9y + -9y

Combine like terms: 8y + -9y = -1y
-1 + -1y = 9y + -9y

Combine like terms: 9y + -9y = 0
-1 + -1y = 0

Add '1' to each side of the equation.
-1 + 1 + -1y = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -1y = 0 + 1
-1y = 0 + 1

Combine like terms: 0 + 1 = 1
-1y = 1

Divide each side by '-1'.
y = -1

Simplifying
y = -1

The perimeter of crater lake is 17.27 miles.

Step-by-step explanation:

Given as :

The shape of the lake is like a circle

The diameter of lake = d = 5.5 miles

∵ shape pf lake is circle, so the diameter of circle = d = 5.5 miles

Let The perimeter of crater lake = p miles

Now, As we know

The perimeter of circle = × diameter

the value of   = 3.14

Or, p =   × d

Or, p =   × 5.5 miles

Or, p =  3.14 × 5.5 miles

∴ p = 17.27 miles

So, The perimeter of circle = perimeter of lake = p = 17.27 miles

Hence, The perimeter of crater lake is 17.27 miles. Answer