Question

Find the value of x in the equation 2x²+3x+3=20​

Answer 1

Answer:

$x= \frac{-3 - \sqrt{145} }{4} \ \ or\ \ x= \frac{-3 + \sqrt{145} }{4}$

Step-by-step explanation:

2x² + 3x + 3 = 20​

⇔ 2x² + 3x + 3 - 20 = 0

⇔ 2x² + 3x - 17 = 0

Using the Quadratic Formula to solve a Quadratic Equation :

$x= \frac{-b \pm \sqrt{b^{2}-4ac} }{2a}$

In the equation 2x² + 3x - 17 = 0

a = 2  ,  b = 3  and c = -17

Then

b² - 4ac = 3² - 4×2×(-17)

           = 9 + 8 × 17    

           = 9 + 136    

           = 145

Then

b² - 4ac > 0

Then

$x= \frac{-3 \pm \sqrt{145} }{2 \times 2}$

Then

$x= \frac{-3 \pm \sqrt{145} }{4}$

Answer 2

Step-by-step explanation:

we first of all move 20 behind the comma for it to become -20 +3 and we get -17.

then use the product =-34

sum = 3

factors then continue