Completing the square??????!?

Question

complete the square

1/8d² -1= -5d

would it be like this
7/8d² +5d-1??? how would you continue this?

thanks for your help=)

Answer 1

Completing the square

1/8d² - 1 = - 5d

Clear the fraction

8(1/8d²) - 8(1) = - 8 (5d)

d² - 8 = - 40d

Transpose

d² - 8 + 40d= - 40d + 40d

d² - 8 + 40d = 0

Transpose

d² - 8 + 40d + 8 = 0 + 8

d² + 40d = 8

d² + 40d +______ = 8 +______

d² + 40d + 400 = 8 + 400

(d + 20)(d + 20) = 408

(d + 20)² = 408

(√d + 20)² = ± √408

d + 20 = ± 20.19900988

d + 20 - 20 = - 20 ± 20.19900988

d = - 20 ± 20.19900988

- - - - - - - -

Solving for +

d = - 20 + 20.19900988

d = 0.199009877

- - - - - - - - -

Solving fkor -

d = - 20 - 20.19900988

d = - 40.09900988

- - - - - - - - s-

Answer 2

You've made a good start.

Remember that 7/8dsquared+5d-1=0

Now you can factor the equation to find d.

Answer 3

1/8d^2+5d-1=0
d^2+40d-8=0
d^2+40d+400-408=0
(d+20)^2=408
d+20=20.199
d=+-0.199