The given equation is
4x + 8x² = 88
That is,
8x² + 4x - 88 = 0
or
2x² + x - 22 = 0
The x-axis intercepts are determined by the solution of the quadratic equation as
x = (1/4) [-1 +/- √(1+176)] = 3.076 or -3.376
Answer: 3.076 or -3.376
Given that the basket of watermelons sells for $9 before tax and the tax rate is 9%.
The tax on the basket of watermelons is given by

Therefore, the total price Tiffany pays for the basket of watermelons is $9 + $0.81 = $9.81