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3 years ago

7

Xiao's teacher asked him to rewrite the sum 60+90 as the product of the GCF of the two numbers and a sum. Xiao's wrote 3(20 + 30

). What mistake did Xiao make? How should he have written the sum?

1 answer:

Kobotan [32]3 years ago

8 0

His answer works ... it gives 150, which is the same as (60 + 90) ... but he didn't deliver exactly what the problem asked for.

It asked for the <u>GCF</u> to be outside the parentheses, and he put '3' there.

'3' is certainly one common factor of 60 and 90, but it's far from being the
greatest one.

The GCF of 60 and 90 is actually 30 . So the absolutely positively technically correct response to the instructions in the problem would be 30(2 + 3).

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A circular path 4 feet wide has an inner diameter of 550 feet. How much farther is it around the outer edge of the path than aro

Softa [21]

Answer:

$L_c=25.12ft$

Step-by-step explanation:

From the question we are told that

Width of circular path $w_c=4ft$

Inner Diameter $d_i_n=550ft$

Outer diameter $d_{out}= 550 +2*4$ (inner diameter + 2 circular path width)

$d_{out}= 550 +8\\d_{out}= 558ft$

Generally the equation for inner circumference of the circle $C_1$ is mathematically given by

$C_1=\pi d_{in}$

$C_1=3.14*550$

$C_1=1727ft$

Generally the equation for outer circumference of the circle $C_2$ is mathematically given by

$C_2=\pi d_{out}$

$C_2=3.14*558$

$C_2=1752.12ft$

Generally the difference in length of the two circumference $L_c$ is mathematically given by

$L_c=C_2-C_1$

$L_c=1752.12-1727$

$L_c=25.12ft$

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3 years ago

only 6 of the 75 trees in the park are at leat 30 feet tall. what percent of the trees are over 30 feet?

ipn [44]

Answer:

8 %

Step-by-step explanation:

To find the percent of trees that are over 30 ft tall, take the number of trees that are over 30 ft tall over the number of tree

Percent = trees over 30 ft tall/ total number of trees

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=.08

Change this to a percent by multiply by 100%

.08 * 100%

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3 years ago

Which equation represents a population of 490 animals that increases at an annual rate of 20% ?

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Answer:

Step-by-step explanation:

The standard form of this exponential function is

$y=a(b)^x$ where a is the initial value and b is the growth rate. Our initial value is 490 and our growth rate is .2 so the equation is

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2 years ago

If f(x) = 4x2 - 5x + 7 and g(x) = 3x2 - 2x + 8, find f(x) + g(x). A) 7x2 - 7x + 15 B) 7x4 - 7x2 + 15 C) 7x2 + 15 D) 12x4 - 8x3 +

lutik1710 [3]

Answer:

A) 7x^2-7x+15

Step-by-step explanation:

f(x) = 4x2 - 5x + 7,

g(x) = 3x2 - 2x + 8

f(x) +g(x) =

4x^2 - 5x + 7 + 3x^2 - 2x + 8=

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3 years ago

8-35. Use your knowledge of polygons to answer the questions below, if possible.

Nataliya [291]

Answer:

(a)I. 13 Sides II. 7 Sides

(b) 4 Sides, Square

(c)x=52 degrees

(d)x=107 degrees

(e)1620 degrees

Step-by-step explanation:

(a)The Sum of the Interior angle of polygon with n sides is derived using the formula: (n-2)180.

I. If the Interior angle is $1980^0$

Then:

$(n-2)180^0=1980^0\\$Divide both sides by 180^0 $ to isolate n$\\n-2=11\\$Add 2 to both sides of the equation\\n-2+2=11+2\\n=13$

The polygon has <u>13 sides.</u>

II. If the Interior angle is $900^0$

Then:

$(n-2)180^0=900^0\\$Divide both sides by 180^0 $ to isolate n$\\n-2=5\\$Add 2 to both sides of the equation\\n-2+2=5+2\\n=7$

The polygon has <u>7 sides.</u>

(b)The sum of the exterior angle of a polygon is 360 degrees,

Each exterior angle of a n-sided regular polygon is: $\frac{360^0}{n}$

If the exterior angle of a regular polygon is 90°

Then:

$90\°=\frac{360^0}{n}\\ 90n=360\\n=4$

The regular polygon has 4 sides and it is called a <u>Square.</u>

<u>(c)</u>The Sum of the Interior angle of polygon with n sides is derived using the formula: (n-2)180.

Each Interior angle of a regular n-sided polygon is: $\frac{(n-2)180^0}{n}$

For a pentagon, n=5

Then:

$\frac{(5-2)180^0}{5}=2x+4\\108=2x+4\\108-4=2x\\104=2x\\x=52^0$

(d)The <u>sum of the exterior angle of a polygon is 360 degrees.</u>

If four of the exterior angles of a pentagon are 57, 74, 56, and 66.

Let the fifth angle=x

Then:

$57+74+56+66+x=360^0\\253+x=360\\x=107^0$

(e)The Sum of the Interior angle of polygon with n sides is derived using the formula: (n-2)180.

In an 11-gon., n=11

Therefore, the sum of the interior angle=(11-2)180= $1620^0$

The sum of the interior angle <u>does not change either in a regular or irregular polygon.</u>

3 0

3 years ago