Solve the equation 2x^2+8x-1=0 by completing the square. Give your answer to 2 decimal places 4 marks

x ≈ - 8.12, x ≈ 0.12

Step-by-step explanation:

Given

x² + 8x - 1 = 0 ( add 1 to both sides )

x² + 8x = 1

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(4)x + 16 = 1 + 16

(x + 4)² = 17 ( take the square root of both sides )

x + 4 = ± ( subtract 4 from both sides )

x = - 4 ±

Thus

x = - 4 - ≈ - 8.12 ( to 2 dec. places )

x = - 4 + ≈ 0.12 ( to 2 dec. places )

step-by-step explanation:

i am not sure sorry : c

-22

times both sides by 2, times () by 8, add alile terms, move terms, add alike and caculate divide both sides by 3