$\bf \textit{vertex of a vertical parabola, using coefficients} \\\\ f(x)=\stackrel{\stackrel{a}{\downarrow }}{2}x^2\stackrel{\stackrel{b}{\downarrow }}{-8}x\stackrel{\stackrel{c}{\downarrow }}{+9} \qquad \qquad \left(-\cfrac{ b}{2 a}~~~~ ,~~~~ c-\cfrac{ b^2}{4 a}\right) \\\\\\ \left(-\cfrac{-8}{2(2)}~~,~~9-\cfrac{(-8)^2}{4(2)} \right)\implies \left( \cfrac{8}{4}~~,~~9-\cfrac{64}{8} \right) \\\\\\ (2~~,~~9-8)\implies (2~~,~~1)$

5 0

3 years ago

Question 9 (1 point)

Likurg_2 [28]

Answer:

A piece of Jewelry costs $4.5 and a hair accessory costs $1.5.

Step-by-step explanation:

Let the price of a piece of jewelry is $x and that of a piece of hair accessories is $y.

So, from the given conditions we can write two different equations as

5x + 8y = 34.5 ............ (1) and

2x + 16y = 33 ............... (2)

Now, solving the equations (1) and (2) we get

2x + 2(34.5 - 5x) = 33

⇒ 8x = 36

⇒ x = $4.5

Again, from the equation (2) we can write

2(4.5) + 16y = 33

⇒ 16y = 24

⇒ y = $1.5

Therefore, a piece of Jewelry costs $4.5 and a hair accessory costs $1.5. (Answer)

6 0

3 years ago