Question

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

Answer 1

Answer:

0

Step-by-step explanation:

0 times anything is zero

Answer 2

ANSWER

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

${x}^{2} - \frac{2}{5} x = 2$

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

${x}^{2} - \frac{2}{5} x + \frac{1}{25} = 2 + \frac{1}{25}$

The left hand side is now a perfect square

$( {x - \frac{1}{5} })^{2} = \frac{51}{25}$

Take square root:

${x - \frac{1}{5} }=\pm \sqrt{\frac{51}{25}}$

${x = \frac{1}{5} }\pm \frac{ \sqrt{51} }{5}$

${x = \frac{1}{5} } - \frac{ \sqrt{51} }{5} \: or \: \: {x = \frac{1}{5} } + \frac{ \sqrt{51} }{5}$

x=-1.2 or x=1.6