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3 years ago

Solve the following by elimination method 11x+15y+23=0 and 7x-2y-20=0

1 answer:

7 0

Let 11x + 15y + 23 = 0 be equation (1)
And 7x - 2y - 20 = 0 be equation (2)

Multiply equation (1) by 2:
22x + 30y + 46 = 0

Multiply equation (2) by 15:
105x - 30y - 300 = 0

Add equations (1) and (2):
22x + 105x + 30y - 30y + 46 - 300 = 0
127x - 254 = 0
127x = 254
x = 254/127
[x = 2]

Substitute x = 2 in equation (1) to find y:
11(2) + 15y + 23 = 0
22 + 15y + 23 = 0
15y + 45 = 0
15y = -45
y = -45/15
y = -3

Therefore, x = 2 and y = -3.

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The dimensions of a conical funnel are shown below: A conical funnel is shown with the height of the cone as 8 inches and the ra

ELEN [110]

Answer:

Step-by-step explanation:

r=3 in

h=8 in

Volume of funnel

$V=\frac{1}{3}\pi r^2h\\=\frac{1}{3} \times 3.14 \times 3^2 \times 8\\=75.36 in.^3\\time ~taken~to~drip out=\frac{75.36}{15}\\\approx 5.02~minutes.$

7 0

2 years ago

Read 2 more answers

According to a 2018 survey by Bankrate, 20% of adults in the United States save nothing for retirement (CNBC website). Suppose t

nalin [4]

Answer:

0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement

Step-by-step explanation:

For each adult, there are only two possible outcomes. Either they save nothing for retirement, or they save something. The probability of an adult saving nothing for retirement is independent of any other adult. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

20% of adults in the United States save nothing for retirement (CNBC website).

This means that $p = 0.2$

Suppose that sixteen adults in the United States are selected randomly.

This means that $n = 16$

What is the probability that three or less of the selected adults have saved nothing for retirement?

This is:

$P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{16,0}.(0.2)^{0}.(0.8)^{16} = 0.0281$

$P(X = 1) = C_{16,1}.(0.2)^{1}.(0.8)^{15} = 0.1126$

$P(X = 2) = C_{16,2}.(0.2)^{2}.(0.8)^{14} = 0.2111$

$P(X = 3) = C_{16,3}.(0.2)^{3}.(0.8)^{13} = 0.2463$

$P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.0281 + 0.1126 + 0.2111 + 0.2463 = 0.5981$

0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement

4 0

2 years ago

What is the area of this parallelogram?

Alex Ar [27]

Formula for area of parallelogram:
A= bh
Where b is the length of base and h is the height.
Here b=2.3+4.5 = 6.8 cm
and h= 4.5 cm
Put values in formula.

A= 6.8 x 4.5
A=30.6 cm²

Answer: 30.6 cm²

7 0

2 years ago

Find 25% of 80 kg A 40kg B 10kg C 8kg D 20kg help me plss

vova2212 [387]

Answer:

25% of 80 is D. 20kg

Step-by-step explanation:

50% of 80 is 40 and we know that 25% is half of 50%, so half of 40 would be 20.

So, the answer is D. 20kg

Hope this helps! :)

8 0

2 years ago