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3 years ago

15 points

Mathematics

1 answer:

valentinak56 [21]3 years ago

5 0

Answer:

43 9/10 miles

Step-by-step explanation:

2(1 3/4) + 2(20 1/5) = 2(7/4) + 2(101/5) = 14/4 + 202/5 = 7/2 + 202/5

common denominator will be 10

7(5) = 35

202(2) = 404

35/10 + 404/10 = 439/10 = 43 9/10 miles

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Can someone explain how to write an equality and how to solve one? I don't understand.

iragen [17]

Okay so the circle on the line plot, if it is empty In the middle it is > or < if it is solid it is ≤ ≥. In this case it not solid so it will be > or < . The plot is at -1 1/2 and is going positive. So it would be a > -1 1/2

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3 years ago

QUICK EASY 25 POINTS!!

MAVERICK [17]

Answer:

1. leave the radical symbol and don't try to convert it to a decimal form

2. The approximated value differs from the exact solution and doesn't give a true equation.

3. Depending on the case, if she needs a mathematical answer, the exact value should be used, but for more practical applications, the rounded decimal form would be more usable.

Step-by-step explanation:

The step by step solution to the equation:

$4x^3=756\\x^3=\frac{756}{4} =189\\x=\sqrt[3]{189} \\x=\sqrt[3]{3^3*7} \\x=3*\sqrt[3]{7}$

1.- Exact solution means that if in the final step when solving for x the value of $x^3$ is not a perfect cube, one needs to leave it indicated as a radical expression (with the radical symbol).

in our case, the cubic root of 189 is not a perfect cube. The factor form of 189 is: $3^3*7$ , so there is a perfect cube factor ( $3^3$ ), but the other factor (7) is a prime number. Therefore 3 can get out of the root, while 7 stays inside.

2.- The equation was solved above, in exact form. Now to solve it giving a decimal approximation, we use a calculator to find the cubic root of 7, which is an irrational number with infinite number of decimals, the first of which we type here: $\sqrt[3]{7} = 1.91293118...$

Therefore, the decimal approximation to the solving for x would be:

$x=3*\sqrt[3]{7}=3*1,91293118...=5.73879...=5.74$

Where we rounded to two decimals as requested.

When we replace the exact answer in the original expression, we get a perfect equality:

$4*x^3=756\\4* (3\sqrt[3]{7} )^3=756\\4*3^3*(\sqrt[3]{7} )^3=756\\4*27*7=756\\\\756=756$

While if we use the approximate answer, we get:

$4*x^3=756\\\\4*(5.74)^3=756\\\\4*189.119224=756\\756.476896=756$

which is NOT a true equality.

3.- I would stick with the idea of showing the exact answer as answer to the mathematical equation. but for a practical case (for example she needs to by some material as a result of her equation solving, it would be more practical to take the numerical approximation to the store, instead of a cubic root of a number.

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3 years ago

What is the range of f(x)=e^x?

Tanzania [10]

The range refers to the value of y for which x is define.

So let y=f(x),

$y = {e}^{x}$

Try making x the subject to obtain,

$x = ln(y)$
x is defined for all real values of y greater than
0.

Hence the correct answer is D.

8 0

3 years ago

Read 2 more answers

A total of $28,000 is invested in two municipal bonds that pay 4.25% and 4.75% simple interest. The investor wants an annual int

Kobotan [32]

Answer:

$16,000 should be invested in the 4.25% bond

Step-by-step explanation:

Attached is the full solution