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Help me with this question I will mark brainlist no web link Solve :- 9n²-64=0

Archy [21]

Factorize

(3n + 8) (3n - 8) = 0
3n + 8 = 0 and 3n - 8 = 0

Solve both for n

3n + 8 = 0
3n = -8
n = -8/3

3n - 8 = 0
3n = 8
n = 8/3

Therefore n = -8/3 and n = 8/3

6 0

3 years ago

What is y + 10 = -3(x + 10) in slope-intercept form?

Inga [223]

Answer:

y= -3x-40

Step-by-step explanation:

first distribute

y+10= -3x-30

than subtract 10

y= -3x-40

4 0

4 years ago

A quantity b varies jointly with c and d and inversely with eWhen b is 18, c is 4, d is 9, and e is 6What is the constant of var

777dan777 [17]

Answer:

constant of variation = 3

Step-by-step explanation:

we know that b varies jointly with c and d

so:

b∝c∝d

and b varies inversely with e, so

b∝ $\frac{1}{e}$

and i will call the constant of variation k, this way we can make an equation for b in the following form:

$b=k\frac{cd}{e}$

this satisfy that b varies jointly with c and d (if b increases, c and d also increase) and inversely with e (if b increases, e decreases)

we know that when b is 18, c is 4, d is 9, and e is 6:

$b=18\\c=4\\d=9\\e=6$

substituting this in our equation for b:

$b=k\frac{cd}{e}\\ 18=k\frac{(4)(9)}{6}$

and we solve operations and clear for the constant of variation k:

$18=k\frac{36}{6}\\ 18=6k\\\frac{18}{6}=k\\ 3=k$

the constant of variation is 3.

4 0

3 years ago

Read 2 more answers

When csc(O)sin(0) is simplified, what is the result?

Olin [163]

Answer:

This is not my answer, it was done by another expert in Brainly.

We are given:

csc (0) * sin (0)

This is to be simplified using trigonometric identities:

csc (x) = 1/sin(x)

so, csc (0) = 1/sin(0)

then,

1/sin(0) * sin (0), the result will be sin(0) / sin (0) which is equal to 1.

Therefore, the answer is 1.

3 0

3 years ago

A college job placement office collected data about students’ GPAs and the salaries they earned in their first jobs after gradua

frez [133]

Answer:

X is the GPA

Y is the Salary

Standard deviation of X is 0.4

Standard deviation of Y is 8500

E(X)=2.9

E(Y)=47200

We are given that The correlation between the two variables was r = 0.72

a) $y = a+bx$

$b = \frac{\sum(x_i-\bar{x})(y_i-\bar{y})}{\sum(x_i-\bar{x})^2} = \frac{r \times \sqrt{var(X) \times Var(Y)}}{Var(X)} = \frac{0.72 \times \sqrt{0.4^2 \times 8500^2}}{0.4^2} = 15300$

$a=y-bx = 47200-(15300 \times 29) = 2830$

So, slope = 15300

Intercept = 2830

So, equation : $y = 2830+15300x$

b) Your brother just graduated from that college with a GPA of 3.30. He tells you that based on this model the residual for his pay is -$1880. What salary is he earning?

$y = 2830+15300 \times 3.3 = 53320$

Observed salary = Residual + predicted = -1860+53320 = 51440

c)) What proportion of the variation in salaries is explained by variation in GPA?

The proportion of the variation in salaries is explained by variation in GPA = $r^2 = (0.72)^2 =0.5184$

8 0

3 years ago