Left is plus right is negative -11-(-15)=4 so you know 4 to the left
I'm not sure what your book is saying about the matter but a cell phone is not usually an essential expense. If it is saying it is though, it would be an essential flexible expense.
We can solve this equation by using the Square Root Method.
First, take the square root of each side of the equation:
(x-8)^2 = 144 becomes x-8 = 12
Then add 8 to both sides.
x=20
The original lawn was d. 20 feet by 20 feet.
(5x+1)² = 7; expand: 25x² + 10x +1 = 7 or 25x² + 10x -6 = 0
Solve this quadratic for x:
x = [-b + √(b² - 4ac)]/2a and x = [-b - √(b² - 4ac)]/2a
Plug the values and you'll find :
x = (- √7 - 1)/5 (answer C)
x = (+√7 -1)/5 (answer E)