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3 years ago

9

Hello I need help in this

1 answer:

maw [93]3 years ago

5 0

There are 22 books total on the shelf and 9 of them are biographical books so the probability is 9/22

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PLEASE HELP ME I WILL MARK BRAINLYEST

Korvikt [17]

Question 9:

Given the equations

$5x+2y=6;$

$4x-8y=0$

solving the system of the equations

$\begin{bmatrix}5x+2y=6\\ 4x-8y=0\end{bmatrix}$

$\mathrm{Multiply\:}5x+2y=6\mathrm{\:by\:}4\:\mathrm{:}\:\quad \:20x+8y=24$

$\mathrm{Multiply\:}4x-8y=0\mathrm{\:by\:}5\:\mathrm{:}\:\quad \:20x-40y=0$

$\begin{bmatrix}20x+8y=24\\ 20x-40y=0\end{bmatrix}$

$20x-40y=0$

$-$

$\underline{20x+8y=24}$

$-48y=-24$

$\begin{bmatrix}20x+8y=24\\ -48y=-24\end{bmatrix}$

$-48y=-24$

$\frac{-48y}{-48}=\frac{-24}{-48}$

$y=\frac{1}{2}$

$y = 0.5$ ( 0.5 is the result of rounding 0.5 to the nearest 0.01)

$\mathrm{For\:}20x+8y=24\mathrm{\:plug\:in\:}y=\frac{1}{2}$

$20x+8\cdot \frac{1}{2}=24$

$20x+4=24$

$\frac{20x}{20}=\frac{20}{20}$

$x=1.00$ ( 1.00 is the result of rounding 1 to the nearest 0.01 )

So, the solution is:

(x, y) → (1.00, 0.5)

Question 10)

Similarly the question 10 can be solved.

Given the equations

$5x+2y=9;\:4x-3y=44$

solving

$\begin{bmatrix}5x+2y=9\\ 4x-3y=44\end{bmatrix}$

$\mathrm{Multiply\:}5x+2y=9\mathrm{\:by\:}4\:\mathrm{:}\:\quad \:20x+8y=36$

$\mathrm{Multiply\:}4x-3y=44\mathrm{\:by\:}5\:\mathrm{:}\:\quad \:20x-15y=220$

$\begin{bmatrix}20x+8y=36\\ 20x-15y=220\end{bmatrix}$

$20x-15y=220$

$-$

$\underline{20x+8y=36}$

$-23y=184$

$\begin{bmatrix}20x+8y=36\\ -23y=184\end{bmatrix}$

$-23y=184$

$y=-8.00$ ( -8.00 Rounded to the nearest 0.01 or the Hundredths Place )

$\mathrm{For\:}20x+8y=36\mathrm{\:plug\:in\:}y=-8$

$20x+8\left(-8\right)=36$

$20x=100$

$x=5.00$ ( 5.00 Rounded to the nearest 0.01 or the Hundredths Place )

So, the solution is:

(x, y) → (5.00, -8.00)

8 0

3 years ago

Convert fraction to decimal

Gennadij [26K]

Where’s the question

5 0

3 years ago

An adult ticket costs $5.25 and a child ticket costs $3.05. If $498.60 were collected for 100 tickets, how many child tickets we

Wewaii [24]

Answer: 12 child tickets

Step-by-step explanation:

We can use system of equations to find how many child tickets were sold. Let's say x is adult and y is child.

Equation 1

5.25x+3.05y=498.6

This equation comes from the cost of tickets.

Equation 2

x+y=100

This equation comes from the number of tickets.

We can use elimination method to solve for y.

5.25x+3.05y=498.6

5.25x+5.25y=525

Now, we can subtract the equations for x to cancel out and to solve for y.

-2.2y=-26.4

y=12

7 0

3 years ago

5d-3+2d=4d+9. I need help can you help me solve this problem

galben [10]

Answer:

D=4

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

Which of the following options have the same value as %25, percent of 64? Choose 2 answers:

Alexxx [7]

Answer:

B and C

Step-by-step explanation:

25% of 64 is 16. So find the two answers that are equivalent to 16.

A: 25*64 = 1600 $\neq$ 16

B: $\frac{25}{100}$ *64 = 16

C: 0.25 * 64 = 16

D: 64/ $\frac{25}{100}$ =256 $\neq$ 16

E: 25/ $\frac{64}{100}$ = 39.06 $\neq$ 16

7 0

3 years ago

Read 2 more answers