65.0k views
1 vote
Which equation shows the quadratic formula used correctly to solve 7x2 = 9 + x for x?

User Odedia
by
8.7k points

2 Answers

1 vote
The equation should be 7x^2 -x-9=0
User Pedro Azevedo
by
7.1k points
4 votes

Answer:

The equation
x=(-(-1)\pm √((-1)^2-4(7)(-9)))/(2(7)) shows the quadratic formula used correctly to solve the given equation.

Explanation:

If a quadratic equation is defined as
ax^2+bx+c=0, then the quadratic formula is


x=(-b\pm √(b^2-4ac))/(2a)

The given equation is


7x^2=9+x

Subtract 9 and x from both the sides.


7x^2-x-9=0

Here, a=7, b=-1 and c=-9.

Substitute a=7, b=-1 and c=-9 in the quadratic formula.


x=(-(-1)\pm √((-1)^2-4(7)(-9)))/(2(7))

Therefore the equation
x=(-(-1)\pm √((-1)^2-4(7)(-9)))/(2(7)) shows the quadratic formula used correctly to solve the given equation.

User Avesse
by
9.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.