What are the approximate solutions of 2x2 + 9x = 8 to the nearest hundredth?
a. x ≈ 1.22 and x ≈ 3.28
b. x ≈ −0.76 and x ≈ 5.26
c. x ≈ −1.22 and x ≈ −3.28
d. x ≈ −5.26 and x ≈ 0.76

Respuesta :

Answer:

The roots of the equations are x ≈ -5.26 and x ≈ 0.76 .

Option (d) is correct.

Step-by-step explanation:

Formula for the roots is given by .

[tex]x = \frac{-b \pm \sqrt{b^{2} -4ac}}{2a}[/tex]

As the equation in the form

[tex]2x^{2} + 9x - 8 = 0[/tex]

As the equation in the form ax² + bx + c = 0

a = 2, b= 9 , c = -8

Put in the formula

[tex]x = \frac{-9 \pm \sqrt{9^{2} -4\times 2\times -8}}{2\times 2}[/tex]

[tex]x = \frac{-9 \pm \sqrt{81 + 64}}{4}[/tex]

[tex]x = \frac{-9 \pm \sqrt{145}}{4}[/tex]

[tex]\sqrt{145} = 12.04[/tex]

Thus First roots be

[tex]x = \frac{-9 - 12.04}{4}[/tex]

[tex]x = \frac{-21.04}{4}[/tex]

x ≈ -5.26

The second root be

[tex]x = \frac{-9 + 12.04}{4}[/tex]

[tex]x = \frac{3.04}{4}[/tex]

x ≈ 0.76

Therefore the roots of the equations are x ≈ -5.26 and x ≈ 0.76 .

Option (d) is correct.




Answer:

the anwser is d, hope this helps