Question

Which of the following are solutions to the equation below?

Check all that apply.
x2 - 8x+ 16 = 5
A. *= V11+ 4
)
B. x= -15+4
O C. x= -15-4
D. x= V5 + 4
E. x= -111-4
OF. x= V5 - 4

Answer 1

x² - 8x+ 16 = 5

x² - 8x + 16 - 5 = 0

x² - 8x + 11 = 0

Using the quadratic formula

x = -b±√b² - 4ac / 2a

a = 1 , b = - 8 c = 11

x = --8±√(-8)² - 4(1)(11) / 2(1)

x = 8 ± √ 64 - 44 / 2

x = 8±√20 / 2

x = 8 - √ 20 / 2 or x = 8 + √ 20 / 2

x = - √ 5 + 4 or x = √5 + 4

Hope this helps