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11 months ago

F(x) = 3x² + 9x – 16 Find f(-8)

Mathematics

1 answer:

Nezavi [6.7K]11 months ago

7 0

Answer: 104

Step-by-step explanation:

$f(-8)$ represents $f(x)$ evaluated at $x=-8$ .

$f(-8)=3(-8)^2 +9(-8)-16\\\\=192-72-16\\\\=120-16\\\\=104$

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Solve the inequality

Mazyrski [523]

The answer would be m ≥ 1 or m ≤ 1/3

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3 years ago

NO LINKS!! Use the method of substitution to solve the system. (If there's no solution, enter no solution). Part 11z

Roman55 [17]

Answer:

$(x,y)=\left(\; \boxed{-1,-8} \; \right)\quad \textsf{(smaller $x$-value)}$

$(x,y)=\left(\; \boxed{5,16} \; \right)\quad \textsf{(larger $x$-value)}$

Step-by-step explanation:

Given system of equations:

$\begin{cases}y=x^2-9\\y=4x-4\end{cases}$

To solve by the method of substitution, substitute the first equation into the second equation and rearrange so that the equation equals zero:

$\begin{aligned}x^2-9&=4x-4\\x^2-4x-9&=-4\\x^2-4x-5&=0\end{aligned}$

Factor the quadratic:

$\begin{aligned}x^2-4x-5&=0\\x^2-5x+x-5&=0\\x(x-5)+1(x-5)&=0\\(x+1)(x-5)&=0\end{aligned}$

Apply the <u>zero-product property</u> and solve for x:

$\implies x+1=0 \implies x=-1$

$\implies x-5=0 \implies x=5$

Substitute the found values of x into the <u>second equation</u> and solve for y:

$\begin{aligned}x=-1 \implies y&=4(-1)-4\\y&=-4-4\\y&=-8\end{aligned}$

$\begin{aligned}x=5 \implies y&=4(5)-4\\y&=20-4\\y&=16\end{aligned}$

Therefore, the solutions are:

$(x,y)=\left(\; \boxed{-1,-8} \; \right)\quad \textsf{(smaller $x$-value)}$

$(x,y)=\left(\; \boxed{5,16} \; \right)\quad \textsf{(larger $x$-value)}$

6 0

1 year ago

Read 2 more answers

Determine whether each point appears on the line with the given slope and y−intercept. Select Yes or No for each point.

-Dominant- [34]

Could you put a graph plz??

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3 years ago

Read 2 more answers

2x+3y=1 and y=-2 - 9 solve using linear combination method. Please explain steps.

kaheart [24]

Answer:

$x=17$

Step-by-step explanation:

$2x+3y=1$

$y=-2-9$

In order to combine these two equations, an idea you need to keep in mind is finding a way of setting these equations as equal to each other. I saw that each equation shared a common value, $y$ . In this case, we need to isolate $y$ in the first equation so that both equations $=y$ .

$2x+3y=1$

$3y=-2x+1$

$\frac{3y}{3}=\frac{-2x+1}{3}$

$y=-\frac{2}{3}x+\frac{1}{3}$

With this, we now know that both $-2-9$ and $-\frac{2}{3}x+\frac{1}{3}$ are equal to $y$ , so we can set them equal to each other.

$y=-\frac{2}{3}x+\frac{1}{3}$

$y=-11$

$-\frac{2}{3}x+\frac{1}{3}=-11$

Reply to this if anything I'm saying or doing is confusing in any way, or if you find a mistake. :) Solve for $x$ .

$-\frac{2}{3}x+\frac{1}{3}=-11$

$-\frac{2}{3}x=-11-\frac{1}{3}$

$-\frac{2}{3}x =-\frac{33}{3}-\frac{1}{3}$

$-\frac{2}{3}x =-\frac{34}{3}$

$-\frac{2}{3}x(-\frac{3}{2})=-\frac{34}{3}(-\frac{3}{2})$

$x=\frac{102}{6}=17$

$x=17$

Hopefully this answer is correct AND makes sense in terms of how I achieved it. Again, reply to this with any questions or mistakes I made and I'll do my best to answer or fix them.

4 0

3 years ago

Allowing 20% discount on the marked price. of 아 a watch, the value of the watch will be Rs. 2378. If the VAT of 10% is added, fi

Harrizon [31]

Answer:

The marked price of the watch is $2,702.27.

Step-by-step explanation:

Since allowing 20% discount on the marked price of a watch, the value of the watch will be Rs. 2378, to determine, if the VAT of 10% is added, it's marked price, the following calculation must be performed:

1 - 0.2 = 0.8

0.8 x 1.1 = 2378

0.88 = 2378

0.8 = X

0.8 x 2378 / 0.88 = X

1,902.4 / 0.88 = X

2,161.81 = X

0.8 = 2,161.81

1 = X

2,161.81 / 0.8 = X

2,702.27 = X

Therefore, the marked price of the watch is 2,702.27.

4 0

2 years ago