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3 years ago

DO THIS PLEASE! STEP BY STEP

Mathematics

1 answer:

Papessa [141]3 years ago

5 0

Answer:

a=5, s=3

Step-by-step explanation:

a=adult s=student

then write 2 equations to represent the amount of people and money

a+s=8

7.25a+5.5s=52.75

• To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.

{a+s=8, 7.25a+5.5s=52.75}

• Choose one of the equations and solve it for a by isolating a on the left hand side of the equal sign.

a+s=8

• Subtract s from both sides of the equation.

a=−s+8

• Substitute −s+8 for a in the other equation, 7.25a+5.5s=52.75.

7.25(−s+8)+5.5s=52.75

• Multiply 7.25 times −s+8.

−7.25s+58+5.5s=52.75

• Add −29s/4 to 11s/2.

−1.75s+58=52.75

• Subtract 58 from both sides of the equation.

−1.75s=−5.25

• Divide both sides of the equation by −1.75, which is the same as multiplying both sides by the reciprocal of the fraction.

s=3

• Substitute 3 for s in a=−s+8. Because the resulting equation contains only one variable, you can solve for a directly.

a=−3+8

• Add 8 to −3.

a=5

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WILL MARK BRAINLIEST <br><br> what is the domain of (f/g) (x)?

tatyana61 [14]

Given that $f(x) = \sqrt{7-x}$ and $g(x) = \sqrt{x + 2}$ , we can say the following:

$\Bigg(\dfrac{f}{g}\Bigg)(x) = \dfrac{f (x)}{g(x)} = \dfrac{\sqrt{7 - x}}{\sqrt{x+2}}$

Now, remember what happens if we have a negative square root: it becomes an imaginary number. We don't want this, so we want to make sure whatever is under a square root is greater than 0 (given we are talking about real numbers only).

Thus, let's set what is under both square roots to be greater than 0:

$\sqrt{7 - x} \Rightarrow 7 - x \geq 0 \Rightarrow x \leq 7$

$\sqrt{x + 2} \Rightarrow x + 2 \geq 0 \Rightarrow x \geq -2$

Since both of the square roots are in the same function, we want to take the union of the domains of the individual square roots to find the domain of the overall function.

$x \leq 7 \,\,\cup x \geq -2 = \boxed{-2 \leq x \leq 7}$

Now, let's look back at the function entirely, which is:

$\Bigg( \dfrac{f}{g} \Bigg)(x) = \dfrac{\sqrt{7 - x}}{\sqrt{x+2}}$

Since $\sqrt{x + 2}$ is on the bottom of the fraction, we must say that $\sqrt{x + 2} \neq 0$ , since the denominator can't equal 0. Thus, we must exclude $\sqrt{x + 2} = 0 \Rightarrow x + 2 = 0 \Rightarrow x = -2$ from the domain.

Thus, our answer is Choice C, or $\boxed{ \{ x | -2 < x \leq 7 \}}$ .

<em>If you are wondering why the choices begin with the $x |$ symbol, it is because this is a way of representing that $x$ lies within a particular set.</em>

6 0

3 years ago

The cost of a unit is made up of $6.25 material cost, $4.75 labour cost, and $3.25 overhead. What is the ratio that exists betwe

blsea [12.9K]

Answer:

The ratio that exist between this three elements are 25 : 19 : 13.

Step-by-step explanation:

Ratio compares one thing to another. Ratios indicate the comparison of the size of a number to another . One trick about ratio is that you can multiply or divide the ratios by same number. For example the ratio of boy to girls can be represented as 3 : 4. If you multiply the ratios by 2 you will get the ratio 6 : 8 and it still represent the same ratios of boys to girls. Ratios can be written as a fraction for example 3/4 for our example.

The cost of the unit is made up of $6.25 , $4.75 and $3.25.

$6.25 $4.75 $3.25 . Let us multiply by 100 to remove the decimals.

625 : 475 : 325 . Now let simplify the ratios by dividing through by 25.

625/25 : 475/25 : 325/25 . The simplest ratios can be written as follows

The ratios are 25 : 19 : 13.

6 0

3 years ago

Help me I'm stuck on this problem

WITCHER [35]

4913 that’s your answer

5 0

3 years ago

There are eight students in a class. Only one of them has passed Exam P/1 and only one of them has passed Exam FM/2. No student

Svetach [21]

Answer: There is probability of 0.57 chances that exactly three students from a group of four students have not passed Exam P/1 or Exam FM/2.

Step-by-step explanation:

Total number of students = 8

Number of student who has passed Exam P/1 = 1

Number of student who has passed Exam FM/2 = 1

No student has passed more than one exam.

According to question, exactly three students from a randomly chose group of four students have not passed Exam P/1 or Exam FM/2.

So, Probability will be

$\frac{^6C_3\times ^2C_1}{^8C_4}\\\\=\frac{20\times 2}{70}\\\\=\frac{4}{7}\\\\=0.57$

Hence, there is probability of 0.57 chances that exactly three students from a group of four students have not passed Exam P/1 or Exam FM/2.

4 0

3 years ago

From data gathered in the period 2008−2012, the yearly value of U.S. exports can be modeled by the function E(x) = −228x3 + 2,25

vredina [299]

Answer:

The total value the U.S. imported and exported is 19364 billion dollars

Step-by-step explanation:

* Lets explain how to solve the problem

- The yearly value of U.S. exports can be modeled by the function

E(x) = −228 x³ + 2,252.8 x² − 6,098.5 x + 11,425.8

# x is the number of years after 2008

# E(x) is the value of exports in billions of dollars

- The yearly value of U.S. imports can be modeled by the function

I(x) = −400.4 x³ + 3,954.4 x² − 11,128.8 x + 17,749.6

# x is the number of years after 2008

# I(x) is the value of imports in billions of dollars

* We need to calculate the total value the U.S. imported and

exported in 2012

∵ x is the number of years after 2008

∴ At 2012 x = 4 years

- Lets calculate the value of the exports in 2012

∴ E(x) = -228(4)³ + 2,252.8(4)² - 6,098.5(4) + 11,425.8

∴ E(x) = 8484.6 billion dollars

- Lets calculate the value of the imports in 2012

∴ I(x) = -400.4(4)³ + 3,954.4(4)² - 11,128.8(4) + 17,749.6

∴ I(x) = 10879.2 billion dollar

∵ The total value the U.S. imported and exported = E(x) + (I(x)

∴ The total value = 8484.6 + 10879.2 = 19363.8

∴ The total value = 19364 billion dollars

* The total value the U.S. imported and exported is 19364 billion dollars

7 0

3 years ago