Use the quadratic formula to solve the equation. x2+7x−4=0 Enter your answers as decimals rounded to the nearest tenth in the boxes. Enter the number only. Do not include the "x ="

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Answer:The solutions are

[0.5, - 7.5]

Step-by-step explanation:

The given quadratic equation is expressed as

x² + 7x - 4 = 0

The given quadratic equation is already in the standard form of

ax² + bx + c

The general formula for solving quadratic equations is expressed as

x = [- b ± √(b² - 4ac)]/2a

From the equation given,

a = 1

b = 7

c = - 4

Therefore,

x = [- 7 ± √(7² - 4 × 1 × - 4)]/2 × 1

x = [- 7 ± √(49 - - 16)]/2

x = [- 7 ± √65]/2

x = (- 7 + √65)/2 or x = (- 7 - √65)/2

x = (- 7 + 8.06)/2 or x = (- 7 - 8.06)/2

x = 0.5 or x = - 7.5

The values of x are either 0.53 or -7.53.

Data;

  • a = 1
  • b = 7
  • c = -4

Quadratic Formula

To solve this problem, we have to use the quadratic formula on this

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

We should substitute the values and solve for the solutions

[tex]y = \frac{-b +- \sqrt{b^2 - 4ac} }{2a}\\y = \frac{-7+- \sqrt{7^2 - 4(1*-4)} }{2*1}\\ y = \frac{-7 +- \sqrt{49 + 16} }{2*1} \\y = \frac{-7+-\sqrt{65} }{2} \\y = \frac{-7+- 8.06}{2} \\y = \frac{-7+8.06}{2} = y = \frac{1.06}{2} = 0.53\\\\or\\y = \frac{-7-8.06}{2}= \frac{-15.06}{2} = -7.53[/tex]

From the above calculation, the values of x are either 0.53 or -7.53.

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