let X equal initial string length
X / 16 = 7.3
X = 7.3 * 16
X = 116.8
Answer:
Step-by-step explanation: add the equations
2x² = 30
x² = 15
y² = 12 - 15
= -3
x4 -y4 = 15² - (-3)²
= 216
ummmmmmmmmm ok cool