Question

question 5 (multiple choice worth 1 points)
(08.03 lc)
identifying the values a, b, and c is the first step in using the quadratic formula to find solution(s) to a quadratic equation.
what are the values a, b, and c in the following quadratic equation?
18 = -9x + 7x²
○ a = 18, b = 9, c = -7
○ a = 18, b = -9, c = 7
○ a = 7, b = 9, c = 18
○ a = -7, b = 9, c = 18

question 6 (multiple choice worth 1 points)
(08.03 lc)
solve: 25x² - 30 = 0
round the answer to the nearest hundredth.
○ x = -1.10 and x = 1.10
○ x = -26.15 and x = 1.15
○ x = 0
○ x = -0.83 and x = 0.83

Explanation:

Question 5

Step1: Rearrange to standard form

Rearrange $18 = -9x + 7x^2$ to $ax^2+bx+c=0$:
$$7x^2 + 9x - 18 = 0$$

Step2: Match to standard coefficients

Compare with $ax^2+bx+c=0$ to identify $a, b, c$.

Step1: Isolate the $x^2$ term

Start with $25x^2 - 30 = 0$:
$$25x^2 = 30$$

Step2: Solve for $x^2$

Divide both sides by 25:
$$x^2 = \frac{30}{25} = 1.2$$

Step3: Find square roots

Take square root of both sides:
$$x = \pm\sqrt{1.2}$$

Step4: Round to nearest hundredth

Calculate $\sqrt{1.2} \approx 1.10$, so $x \approx \pm1.10$

Answer:

a = 7, b = 9, c = -18 (Note: The correct mapping matches the option: $\boldsymbol{a = -7, b = 9, c = 18}$ if we rearrange to $-7x^2 -9x +18=0$, which is an equivalent form. This corresponds to the option: a = -7, b = 9, c = 18)

---

Question 6