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Which equation shows the quadratic formula used correctly to solve 7x^2 = 9 + x for x?

Which equation shows the quadratic formula used correctly to solve 7x^2 = 9 + x for-example-1

2 Answers

2 votes

Answer:

Explanation:

We must rewrite 7x^2 = 9 + x in standard form first: 7x^2 - x - 9 = 0.

The coefficients are 7, -1 and -9, and so the discriminant b^2 - 4ac is

(1)^2 - 4(7)(-9) = 253.

The roots are:

-(-1) ± √253 1 ± √253

x = --------------------- = --------------------

2(7) 14

User JaredPar
by
8.0k points
3 votes

The correct quadratic formula to solve
\(7x^2 = 9 + x\) is
\(x = (1 \pm √(1 - 4(7)(-9)))/(2(7))\). The accurate representation is given in option B.

The correct quadratic formula for solving
\(7x^2 = 9 + x\) is represented as follows:


\[ x = (-b \pm √(b^2 - 4ac))/(2a) \]

Comparing this with the provided options:

A. Incorrect. The term inside the square root is incorrect; it should be
\(9 - 4(7)(1)\).

B. Correct. The quadratic formula is used correctly with the correct values for a, b, and c.

C. Incorrect. The term inside the square root is incorrect; it should be
\((-1)^2 - 4(7)(9)\).

D. Incorrect. The term inside the square root is incorrect; it should be
\((-1)^2 - 4(7)(9)\).

Therefore, the correct answer is B:


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

User Alec Bennett
by
8.2k points

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