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3 years ago

When solving for x, what is x squared plus 15 equals -8x

Mathematics

1 answer:

VLD [36.1K]3 years ago

5 0

Answer:

x = - 5, x = - 3

Step-by-step explanation:

Given

x² + 15 = - 8x ( add 8x to both sides )

x² + 8x + 15 = 0 ← in standard form

Consider the factors of the constant term (+ 15) which sum to give the coefficient of the x- term (+ 8)

The factors are 5 and 3, since

5 × 3 = 15 and 5 + 3= 8, thus

(x + 5)(x + 3) = 0 ← in factored form

Equate each factor to zero and solve for x

x + 5 = 0 ⇒ x = - 5

x + 3 = 0 ⇒ x = - 3

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Jim is riding his bike home from school. the school is 9 miles from his house and he rides his bike at a constant speed of 12 mi

Natalka [10]

Answer:

I think that it would be d because 9 is 3/4 of 12 and 45 is 3/4 of 60

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3 years ago

I learn maths and I don't know how to solve this problem.

Lyrx [107]

Answer:

As we get closer to x=-3, the limit is approaches -1, on both sides of -3 so this is a good limit so c is 8.

Step-by-step explanation:

In order for a limit to exists, the left side limit must exist and right side limit must exist and on top of that, they must be equal to each other.

In this case, this a piece wise function and by definition of a limit that exist, the limit of this piece wise function as x approaches 3 from either side, must be equal.

We let x=-3 for the top equation.

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So we set the second equation equal to -1.

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$c = 8$

So the value of c is 8. We can prove this by graphing as well.

5 0

2 years ago

Awsner this with step by step (can use calculator)

ss7ja [257]

Answer:

$x = 9.2$

$x =22.0$

$x = 8.7$

Step-by-step explanation:

Required

Find x

(a)

x is calculated using tangent formula

$\tan(57) = \frac{x}{6}$

Make x the subject

$x = 6 * \tan(57)$

$x = 6 * 1.5399$

$x = 9.2394$

$x = 9.2$ --- approximated

(b):

x is calculated using cosine formula

$\cos(60) = \frac{11}{x}$

Make x the subject

$x = \frac{11}{\cos(60)}$

$x = \frac{11}{0.5}$

$x =22.0$

(c):

x is calculated using sine formula

$\sin(60) = \frac{x}{10}$

Make x the subject

$x = 10 * \sin(60)$

$x = 10 * 0.8660$

$x = 8.660$

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3 0

3 years ago

Help, I need it by 9:00 am

olya-2409 [2.1K]

<h3>Answer:</h3>

Option B. because all rational numbers are integers.

Have a look at the above venn diagram showing the relationship between - Real, irrational, rational, integers, whole and natural numbers.

$\longrightarrow{\green{Option \: B.}}⟶Option \: B.$

4 0

2 years ago

Solve the system by substitution.<br> -8x – 7y = -5<br> -x = y

Lapatulllka [165]

Substitute y = -x into the first equation:

-8x - 7(-x) = -5

-8x + 7x = -5

-x = -5

x = 5

Substitute x = 5 into y = -x

y = -(5)

y = -5

Answer: x = 5, y = -5

6 0

3 years ago

Read 2 more answers