Solve by using tables. Give each answer to at most two decimal places. –2x2 – 4 = –8x (1 point) 0.59, 3.41 –3.41, –0.59 1.17, 6.83 –1.41, 1.41
Answer
0.59, 3.41
Explanation
–2x2 – 4 = –8x is a quadrilatic equation
–2x2 – 4 = –8x ⇒ -2x² + 8x - 4 = 0
2x² - 8x + 4 = 0
x² - 4x + 2 = 0
Using the complete square method to solve;
x² - 4x = -2
x² - 4x + 2² = -2 + 2²
(x - 2)² = 2
x - 2 = √2
x = √2 + 2
∴ x = 1.414 + 2 or x = -1.414 + 2
x = 3.414 x = 0.5858
= 3.41 = 0.59
Answer:
x=3.414 and x=0.59 is the desired answer.
Step-by-step explanation:
We are given a quadratic equation as : \(-2x^2-4=-8x\\=> 2x^2-8x+4=0\)
on dividing both side by 2 we have the equation as
\(x^2-4x+2=0\)
on solving for the roots of the equation using the quadratic formula we get that \(x=2\pm \sqrt{2}\)
\(x=2+\sqrt{2}\) and \(x=2-\sqrt{2}\)
x=2+1.414 and x=2-1.414
Hence , x=3.414 and x=0.586≈0.59.