Find the sum and product of the roots. 7x 2 - 3x - 9 = 0

7x^2-3x-9=0
applying the quadratic formula we get:
x=[-b+/-sqrt(b^2-4ac)]/(2a)
x=[-(-3)+/-sqrt((-3)^2-4*7*(-9))]/(2*7)
x=[3+/-sqrt(9+252)]/14
x=[3+/-sqrt162]/14
hence
x=[3+/-16.1555]/14
x=1.3682 or -0.9396
thus the sum of the roots will be:
(1.3682+(-0.9396))=0.4286
the product will be:
(1.3682)(-0.9396)
=-1.28556

Answer Link

slicergiza slicergiza · Answer 2 · 2019-07-24T19:46:01+02:00

Answer:

Sum of the roots is [tex]\frac{3}{7}[/tex]

Product of the roots is [tex]-\frac{9}{7}[/tex]

Step-by-step explanation:

In a quadratic equation ax² + bx + c = 0,

Sum of the roots = [tex]-\frac{b}{a}[/tex]

And, product of the roots = [tex]\frac{c}{a}[/tex]

Here, the given quadratic equation,

[tex]7x^2-3x-9=0[/tex]

Hence,

Sum of the roots = [tex]-\frac{-3}{7}[/tex] = [tex]\frac{3}{7}[/tex]

Product of the roots = [tex]\frac{-9}{7}[/tex] = [tex]-\frac{9}{7}[/tex]