Answer: i may be wrong but is it 4?
the answer to this problem is 4
Multiply numerator and denominator by the conjugate of the denominator
Denominator: -10 + 8i
Conjugate of the denominator: -10 - 8i
Operation:
[9 +7i] / [-10 + 8i] * [-10 -8i] / [-10 - 8i] = [-90 - 72i - 70i +56] / [100 + 64] =
[-34 -142i] / 164 = [-17 -71i] / 82
The answer is They left a 20% tip, so the service was probably above average. First step is to the amount of the sales tax. If 100% is $73.89, 5.8% will be x (tax): 100% : $73.89 = 5.8% : x. x = $73.89 * 5.8% : 100%. x = $4.28. Now, we have the price for meals, sales tax, and the total amount of money left, so we can calculate how much the tip is: $93.00 - $73.89 - $4.28 = $14.83. So, the tip is $14.83. Let represent it as percent. If $73.89 is 100%, $14.83 will be x. $73.89 : 100% = $14.83 : x. x = $14.83 * 100% : $73.89. x = 20%. So, they left a 20% tip, so the service was probably above average.
*HOPE I HELPED!*
