Respuesta :
Answer:
2.57 or -0.907
Step-by-step explanation:
→ First state the quadratic formula
[tex]\frac{-b+-\sqrt{b^{2}-4ac } }{2a}[/tex]
→ Identify the 'a', 'b' and 'c' variables
[tex]ax^{2} +bx+c[/tex]
[tex]3x^{2} -5x-7[/tex]
a = 3, b = -5 and c = -7
→ Substitute in the values into the quadratic formula
[tex]\frac{5+\sqrt{5^{2}-4*3*-7 } }{2*3}=\frac{5+\sqrt{25+84 } }{6}=\frac{5+\sqrt{109 } }{6}=2.573384418[/tex]
→ Do the same for negative
[tex]\frac{5-\sqrt{5^{2}-4*3*-7 } }{2*3}=\frac{5-\sqrt{25+84 } }{6}=\frac{5-\sqrt{109 } }{6}=-0.9067177515[/tex]
The two solutions of the quadratic equation are:
- x = -2.573
- x = 0.907.
How to solve a quadratic equation?
For a general quadratic equation:
a*x^2 + b*x + c = 0
The solutions are given by:
[tex]x = \frac{-b \pm \sqrt{b^2 - 4ac} }{2a}[/tex]
In this case we have:
3x^2 + 5x - 7 = 0
Then:
- a = 3
- b = 5
- c = -7.
Replacing that in the formula we get:
[tex]x = \frac{-5 \pm \sqrt{5^2 - 4*3*(-7)} }{2*3}\\\\x = \frac{-5 \pm 10.44 }{6}[/tex]
Then the two solutions are:
- x = (-5 + 10.44)/6 = 0.907
- x = (-5 - 10.44)/6 = -2.573
If you want to learn more about quadratic equations, you can read:
https://brainly.com/question/1214333