Question

Use the quadratic formula to solve the equation. -2x^2 -x+7=0

Answer 1

x = 1.637 or x = -2.137

Explanation:

Given equation is:

-2x²-x+7 = 0

ax²+bx+c = 0 is general quadratic equation.

x = (-b±√b²-4ac) / 2a is quadratic equation to solve the quadratic equations.

Comparing general equation with given equation , we have

a = -2 , b = -1 and c= 7

Putting the given values in quadratic formula, we have

x = (-(-1)±√(-1)²-4(-2)(7) ) / 2(-2)

x = (1±√1+56) / (-4)

x = (1±√57) / (-4)

x = (1±7.549) / (-4)

x = 1-7.549 / (-4) or x = (1+7.549) / (-4)

x = -6.549 / -4 or 8.549 / (-4)

x = 1.637 or x = -2.137 is the solution.

Answer 2

Answer:
`x_1=1.63\\x_2=-2.13`

Explanation:

1. The quadratic formula is shown below:

`x=\frac{-b+/-\sqrt{b^(2)-4ac}}{2a}`

2. Given the quadratic equation given in the problem, you have that:

`a=-2\\b=-1\\c=7`

3. Therefore, when you substitute the values shown above, you obtain the following result:

`x=\frac{-(-1)+/-\sqrt{(-1)^(2)-4(-2)(7)}}{2(-2)}`

`x_1=1.63\\x_2=-2.13`