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3 years ago

Which of the following is a solution to the equation 0=x2+6x+4 ?

Mathematics

1 answer:

Llana [10]3 years ago

4 0

Answer:

Step-by-step explanation:

Given

x² + 6x + 4 = 0 ( subtract 4 from both sides )

x² + 6x = - 4

Solve using the method of completing the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(3)x + 9 = - 4 + 9, that is

(x + 3)² = 5 ( take the square root of both sides )

x + 3 = ± $\sqrt{5}$ ( subtract 3 from both sides )

x = - 3 ± $\sqrt{5}$ , thus

x = - 3 - $\sqrt{5}$ → A

x = - 3 + $\sqrt{5}$

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Graph the function.

RideAnS [48]

Answer:

$\displaystyle{y=-3x-1}$

Step-by-step explanation:

I have two methods: <u>standard-learning</u> which will explain overall mathematically - basically formula, etc. - while the other one <u>trick-tips</u> method will rely on choices rather mathematical calculations but with explanation on <em>why</em> and <em>how.</em>

<h3>Standard-Learning</h3>

First, let’s pick two points that are integers since they are easily to be found via graphs. We see that (-1,2) and (0,-1) is a part of the graph so now we finally have picked two points for our calculations.

When we have finally picked two points, we will be using them for <u>slope calculation</u>. This part is <u>crucial</u> for finding an equation of a line because a line has to contain slope in its equation.

To calculate the slope, we use rise over run formula which is:

$\displaystyle{\dfrac{\Delta y}{\Delta x} = \dfrac{y_2-y_1}{x_2-x_1}}$

Note that $\displaystyle{\Delta}$ is delta - in both mathematic and physics, it means <u>changes in</u>.

So, we will be using those two points that we have picked to substitute in the slope formula. Let’s determine that $\displaystyle{(x_2,y_2)=(-1,2)}$ and $\displaystyle{(x_1,y_1)=(0,-1)}$ .

Therefore, our slope will be:

$\displaystyle{m=\dfrac{2-(-1)}{-1-0}}\\\\\displaystyle{m=\dfrac{2+1}{-1}}\\\\\displaystyle{m=-3}$

Next, find the y-intercept. From the graph, we see that the graph intercepts at (0,-1) which is y-intercept so we will only use y-value. Hence, b = -1.

From the slope-intercept form:

$\displaystyle{y=mx+b}$

Substitute m (slope) = -3 and b (y-intercept) = -1. Hence, the equation of line is:

$\displaystyle{y=-3x-1}$

<h3>Fast Way (Trick-Tips)</h3>

Relying on choices and knowledge of graph, notice that there are slopes of 3 and -3.

Keep in mind that if slope is negative, it will decrease down and if slope is positive, it will increase up.

Therefore, cut off all choices with positive slopes which are 1 and 3. We are now left with 2 and 4.

Next, look at the graph and tell its y-intercept. It intercepts y at y = -1 so we take value of -1.

So choice 4 is cut off and now we have choice 2 as the answer.

Learn More:

brainly.com/question/27514958 - Find the line equation with given points

8 0

2 years ago

A box of granola bars contains 3 chocolate chip bars, 2 peanut butter bars, 1 lemon bar, and 4 raisin bars. Iesha will randomly

ella [17]

Answer:

2/45

Step-by-step explanation:

Note this selection is done without replacement hence after each selection sample size will reduce

Given data

Samples 3 chocolate chip bars,

2 peanut butter bars,

1 lemon bar, and

4 raisin bars

Sample size S= [3+2+1+4]= 10

Probability that first selection is lemon = 1/10

Probability that second selection is raisin = 4/9

Hence the probability that the first bar Iesha selects will be lemon and the second will be raisin= 1/10*4/9

= 4/90= 2/45

3 0

3 years ago

Angelica says the tangent is the ratio of the length of the leg opposite angle A ∠ A over the length of the leg adjacent to angl

Tpy6a [65]

Based on the trigonometry ratios and the Pythagorean theorem both of them were incorrect.

Cos A = 4/5; Sin A = 3/5

<h3>What is the Trigonometry Ratios?</h3>

The Trigonometry ratios relates the length of the sides of a right triangles. They are given as:

Sine ratio, sin ∅ = opp/hyp
Cosine ratio, cos ∅ = adj/hyp
Tangent ratio, tan ∅ = opp/adj.

<h3>What is the Pythagroean Theorem?</h3>

If two sides of a right triangle are known the third side can be determined using the Pythagorean theorem, which is given as, c² = a² + b², where and b are legs, and c is the hypotenuse of the right triangle.

1. Given that tan A = 3/4, it is not necessarily true that BC MUST have a length of 3 units, and AC MUST have a length of 4 units, because:

If BC = 9 units and AC = 12 units, the it will give us the same tangent ratio as:

tan A = 9/12 = 3/4.

Therefore, Angelica's mistake is stating that BC MUST be 3 units, and AC MUST be 4 units.

2. Knowing two length of the sides of a right triangle is enough information needed to find the length of the third side using the Pythagorean theorem, so Graceilla is incorrect.

3. Find AC using the Pythagorean theorem:

AB = √(3² + 4²)

AB = 5 units.

Cos A = adj/hyp = AC/AB

Cos A = 4/5

Sin A = opp/hyp = BC/AB

Sin A = 3/5

Learn more about the trigonometry ratios on:

brainly.com/question/10417664

3 0

2 years ago

Write "3 x 3 x 5 x 5" in exponential form.

Tomtit [17]

Answer:

225xxx 3

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

A line passes through the point (8,-9) and has a slope of -5/2. Write an equation in slope intercept form for this line.

noname [10]

Answer:

y = - $\frac{5}{2}$ x + 11

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - $\frac{5}{2}$ , then

y = - $\frac{5}{2}$ x + c ← is the partial equation

To find c substitute (8, - 9) into the partial equation

- 9 = - 20 + c ⇒ c = - 9 + 20 = 11

y = - $\frac{5}{2}$ x + 11 ← equation of line

4 0

3 years ago