Answer:
4
Step-by-step explanation:
7x = x² - 8
=> x² - 7x - 8 = 0
use quadratic formula:
a = 1, b = -7, c = -8
x = [tex]\frac{-(1)±\sqrt{(-7)^{2} - 4(1)(-8) } }{2(1)}[/tex] (pls ignore the "A" I don't know why it's showing up)
=> x = [tex]\frac{-1±\sqrt{49 + 32} }{2}[/tex]
=> x = [tex]\frac{-1±9 }{2}[/tex]
=> x = [tex]\frac{-1 +9}{2}[/tex] = 4 or [tex]\frac{-1-9}{2}[/tex] = -5 (the answer is only 4 since it's asking for the positive solution)
