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3 years ago

Multiply (2-5i)(2+5i)

Mathematics

1 answer:

Ksenya-84 [330]3 years ago

7 0

Answer:

Step-by-step explanation:

4 - 25i^2

4 - 25x(-1)

4 + 25 = 29

the ^2 means exponent 2

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Complete the solution of the equation. Find the value of y when x equals -2. -4x+8y=-24

zepelin [54]

Answer:y=-4

Step-by-step explanation:

Multiply -4 by -2 you get positive 8 rewrite the equation subtract 8 from both sides that leaves you with 8y=-32 your final step is to divide both sides 8 that leaves you with -4 which is the answer.

5 0

3 years ago

Read 2 more answers

I will give you brainlist if you answer this question in 5 mintues

algol [13]

(2,3)??? Maybe? I really don’t know

4 0

3 years ago

PLEASE HELP! Which ordered pairs are solutions to the inequality y-4x (greater than or equal to) -5? Select each correct answer

Wittaler [7]

(-2, 1), (-4, 2) and (1, -1) are solutions to given inequality y-4x (greater than or equal to) -5

Solution:

Given, inequality is y – 4x ≥ - 5

We have to find the correct answers from given options

We have to check option by option.

Now, (-2, 1) ⇒ 1 – 4(-2) ≥ - 5 ⇒ 1 + 8 ≥ -5 ⇒ 9 ≥ -5 ⇒ correct answer.

Now, (-4, 2) ⇒ 2 – 4(-4) ≥ -5 ⇒ 2 + 16 ≥ - 5 ⇒ 18 ≥ - 5 ⇒ correct answer

Now, (1, -1) ⇒ -1 – 4(1) ≥ - 5 ⇒ -1 – 4 ≥ - 5 ⇒ -5 ≥ -5 ⇒ correct answer

Now, (4, 0) ⇒ 0 – 4(4) ≥ - 5 ⇒ -16 ≥ -5 ⇒ wrong answer

Now, (5, -2) ⇒ -2 – 4(5) ≥ - 5 ⇒ -2 – 20 ≥ -5 ⇒ -22 ≥ -5 ⇒ wrong answer

Hence, (-2, 1), (-4, 2) and (1, -1) are solutions to given inequality.

8 0

3 years ago

Memory module consists of 9 chips. The device is designed with redundancy so that it works even if one of its chips is defective

soldier1979 [14.2K]

Answer:

a) $P[C]=p^n$

b) $P[M]=p^{8n}(9-8p^n)$

c) n=62

d) n=138

Step-by-step explanation:

Note: "Each chip contains n transistors"

a) A chip needs all n transistor working to function correctly. If p is the probability that a transistor is working ok, then:

$P[C]=p^n$

b) The memory module works with when even one of the chips is defective. It means it works either if 8 chips or 9 chips are ok. The probability of the chips failing is independent of each other.

We can calculate this as a binomial distribution problem, with n=9 and k≥8:

$P[M]=P[C_9]+P[C_8]\\\\P[M]=\binom{9}{9}P[C]^9(1-P[C])^0+\binom{9}{8}P[C]^8(1-P[C])^1\\\\P[M]=P[C]^9+9P[C]^8(1-P[C])\\\\P[M]=p^{9n}+9p^{8n}(1-p^n)\\\\P[M]=p^{8n}(p^{n}+9(1-p^n))\\\\P[M]=p^{8n}(9-8p^n)$

$P[M]=(0.999)^{8n}(9-8(0.999)^n)=0.9$

This equation was solved graphically and the result is that the maximum number of chips to have a reliability of the memory module equal or bigger than 0.9 is 62 transistors per chip. See picture attached.

d) If the memoty module tolerates 2 defective chips:

$P[M]=P[C_9]+P[C_8]+P[C_7]\\\\P[M]=\binom{9}{9}P[C]^9(1-P[C])^0+\binom{9}{8}P[C]^8(1-P[C])^1+\binom{9}{7}P[C]^7(1-P[C])^2\\\\P[M]=P[C]^9+9P[C]^8(1-P[C])+36P[C]^7(1-P[C])^2\\\\P[M]=p^{9n}+9p^{8n}(1-p^n)+36p^{7n}(1-p^n)^2$

We again calculate numerically and graphically and determine that the maximum number of transistor per chip in this conditions is n=138. See graph attached.

6 0

4 years ago

What is b-4z/7=a in algebraic form?

Lera25 [3.4K]

(b - 4z)/7 = a
b - 4z = 7a
b = 7a + 4z

Answer: b = 7a + 4z

8 0

3 years ago