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3 years ago

How can you use mental math and properties to help you multiply numbers?

1 answer:

4 0

<span>You can use mental math to help you multiply numbers by using the distributive property to divide it easily and then add them up to get a quick answer. You can also use mental math by using the commutative property as a quick reminder. If you have 7 + 10 and the next problem is 10 + 7, you know the answer will be the same, 17.</span>

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A scale drawing of a field is shown below. The drawing uses a scale of 1 in. = 14 ft. What is the area of the actual field?

svp [43]

Answer:

D. 4,704 ft²

Step-by-step explanation:

Giving a scale of 1 in. = 14 ft, to find the actual area of the field represented by the triangular drawing above, convert the length of the base and height to the actual lengths of the field using the scale.

Height of drawing = 8 in.

Actual height = 8*14 = 112 ft

Base of drawing = 6 in.

Actual base = 6*14 = 84 ft

Area of the field = area of ∆

Area = ½*base*height

Area = ½*84*112

Area = 4,704 ft²

3 0

3 years ago

An individual who has automobile insurance from a certain company is randomly selected. Let Y be the number of mov- ing violatio

Rudik [331]

Answer:

a) E(y) = 0.8

b) The average subcharge is $165

Step-by-step explanation:

We are given the following distribution in the question:

y: 0 1 2 3

P(y): 0.50 0.25 0.20 0.05

a) E(y)

$E(y) = \displaystyle\sum y_iP(y_i)\\\\E(y) = 0(0.50)+1(0.25)+2(0.20)+3(0.05)\\E(y) = 0.8$

b) Expected value of subcharge

Subcharge =

$\$110y^2$

Expected value of subcharge =

$=110E(y^2)\\\\=110\displaystyle\sum y_i^2P(y_i)\\\\=110(0^2(0.50)+1^2(0.25)+2^2(0.20)+3^2(0.05))\\=110(1.5)=165$

Thus, the average subcharge is $165

5 0

3 years ago

What is the difference between a factor of a number and a multiple of a number? use the number 25 has an example

Ne4ueva [31]

Answer:

factor: a submultiple; an integer value that gives an integer quotient when the number is divided by it.
multiple: the product of the number and another integer

Step-by-step explanation:

<h3>Factors</h3>

A set of factors of a number (N) is a set of integers {f1, f2, f3, ...} whose product is the number:

f1 × f2 × f3 × ... = N

Often the term "factors" is used to mean "prime factors," the set of prime numbers whose product is N.

When N = 25, the prime factors are {5, 5}. That is ...

5×5 = 25

<h3>Divisors</h3>

A "divisor" of a number is a sub-multiple of N. That is, the quotient N/k is an integer for some divisor k of N. Usually, we're interested in integer divisors. All prime factors will be integer divisors of N. The term "factor" is often used when the term "divisor" is meant.

Divisors of N = 25 include 1, 5, and 25. There will be an odd number of integer divisors (as here) if the number N is a perfect square.

<h3>Multiples</h3>

For an integer k, the value k×N is called a <em>multiple</em> of N, often, the <em>k-th multiple</em> of N.

Multiples of 25 include 25, 50, 75, 100, 125, and any other decimal number ending in 25, 50, 75, or 00.

<em>Another example</em>

When N=30, the prime factors are {2, 3, 5}. The divisors are {1, 2, 3, 5, 6, 10, 15, 30}. (Note there are an even number of divisors.) Multiples of 30 include 30, 60, 90, 120, ....

6 0

2 years ago

I don't understand what's the answer

gayaneshka [121]

The correct answer is D. 36 x 1/9
When there is a negative exponent on a whole number:
4 ^-2
1/ 4 ^2 = 1b16

6 0

4 years ago

-0.38 (8 repeating) written as a fraction is _____.

natulia [17]

Answer:

$\frac{7}{18}$