Question

PLEASE HELP!!!!!!! Solve for x. Use the completing the square method. 5x2−2x−10=0 Round decimals to the nearest tenth.

Answer 1

0

Explanation:

0 times anything is zero

Answer 2

x=-1.2 or x=1.6

EXPLANATION

The given equation is:

`5{x}^(2) - 2x - 10 = 0` Group and combine the constant terms:

`5{x}^(2) - 2x = 10`

Divide through by 5

`{x}^(2) - (2)/(5) x = 2`

Add the square of the coefficient of x to both sides:

`{x}^(2) - (2)/(5) x + (1)/(25) = 2 + (1)/(25)`

The left hand side is now a perfect square

`( {x - (1)/(5) })^(2) = (51)/(25)`

Take square root:

`{x - (1)/(5) }=\pm \sqrt{(51)/(25)}`

`{x = (1)/(5) }\pm ( √(51) )/(5)`

`{x = (1)/(5) } - ( √(51) )/(5) \: or \: \: {x = (1)/(5) } + ( √(51) )/(5)`

x=-1.2 or x=1.6