All categories

2 years ago

7th grade math help me pleaseee

Mathematics

2 answers:

yarga [219]2 years ago

7 0

Answer:

A= 2^4= 16

B=10^5=100,000

Step-by-step explanation:

A= 2*2=4*2=8*2=16

B=10*10=100*10=1000*10=10,000*10=100,000

Hope this helps!! Please consider marking brainliest! Have a good one!!

GrogVix [38]2 years ago

5 0

A = 8

B = 50

Step-by-step explanation:

You might be interested in

All positive integers whose digits add up to 11 are listed in increasing order: 29, 38, 47, ... What is the eleventh number in t

amm1812

Answer:

119

Step-by-step explanation:

29, 38, 47, 56, 65, 74, 83, 92, 101, 110, 119, 128, 137, 146, 155

3 0

2 years ago

How is the product of 3 and 2 shown on a number line?

erastova [34]

Answer:

A number line going from negative 7 to positive 7. An arrow goes from 0 to 3 and from 3 to 6.

4 0

3 years ago

The pyramid of Khafre measured 143.5 meters high. The pyramid of Menkaure measured 65.5 meters high. Write and solve an equation

steposvetlana [31]

Answer:

See below

Step-by-step explanation:

The pyramid of Khafre measured 143.5 meters high.
The pyramid of Menkaure measured 65.5 meters high.

<u>The difference in the heights of the two pyramids:</u>

d = 143.5 m - 65.5 m
d = 78 m

3 0

2 years ago

Consider the vectors a =3i +j −k, b =i +j +4k, c=i +3j +k, d =−i −3j +k, g =−3i −j +k. Which pairs (if any) of these vectors are

11111nata11111 [884]

Answer:

a and b are perpendicular to each other, as are b and d, b and g

Step-by-step explanation:

To check whether two vectors are perpendicular to each other, we need the angle between these vectors to be 90 degrees.

We can find the angle between to vectors a and b from the following relation:

The cosine of the angle $\theta$ between two vectors is equal to the dot product of this vectors divided by the product of vector magnitude.

$cos(\theta) = \frac{a.b}{|a||b|}$

cos(90) = 0, so when the dot product between vectors a and b is 0, it means that these vectors are perpendicular to each other.

Now, for your exercise, let's compute the dot product between these vectors.

-----------

a.b = (3,1,-1).(1,1,4) = 3+1-4 = 0

So a and b are perpendicular to each other.

------------

a.c = (3,1,-1).(1,3,1) = 3+3-1 = 5

a and c are not perpendicular to each other.

--------------

a.d = (3,1,-1).(-1,-3,1) = -3-3-1 = -7

So not perpendicular

---------------

a.g = (3,1,-1).(-3,-1,1) = -9-1-1 = -11

Not

-----------------

b.c = (1,1,4).(1,3,1) = 1+3+4 = 8

Not

------------------

b.d = (1,1,4).(-1,-3,1) = -1 -3 +4 = 0

b.d = 0, so b and d are perpendicular to each other

--------------------

b.g = (1,1,4).(-3,-1,1) = -3-1+4 = 0

b.g = 0, perpendicular

---------------------

c.d = (1,3,1).(-1,-3,1) = -1-9+1 = -9

-----------------------

c.g = (1,3,1).(-3,-1,1) = -3-3+1 = -5

------------------------

d.g = (-1,-3,1).(-3,-1,1) = 3+3+1 = 7

7 0

3 years ago

An open metal tank of square base has a volume of 123 m^3

snow_lady [41]

Answer:

a) h = 123/x^2

b) S = x^2 +492/x

c) x ≈ 6.27

d) S'' = 6; area is a minimum (Y)

e) Amin ≈ 117.78 m²

Step-by-step explanation:

a) The volume is given by ...

V = Bh

where B is the area of the base, x^2, and h is the height. Filling in the given volume, and solving for the height, we get:

123 = x^2·h

h = 123/x^2

b) The surface area is the sum of the area of the base (x^2) and the lateral area, which is the product of the height and the perimeter of the base.

$S=x^2+Ph=x^2+(4x)\dfrac{123}{x^2}\\\\S=x^2+\dfrac{492}{x}$

c) The derivative of the area with respect to x is ...

$S'=2x-\dfrac{492}{x^2}$

When this is zero, area is at an extreme.

$0=2x -\dfrac{492}{x^2}\\\\0=x^3-246\\\\x=\sqrt[3]{246}\approx 6.26583$

d) The second derivative is ...

$S''=2+\dfrac{2\cdot 492}{x^3}=2+\dfrac{2\cdot 492}{246}=6$

This is positive, so the value of x found represents a minimum of the area function.

e) The minimum area is ...

$S=x^2+\dfrac{2\cdot 246}{x}=(246^{\frac{1}{3}})^2+2\dfrac{246}{246^{\frac{1}{3}}}=3\cdot 246^{\frac{2}{3}}\approx 117.78$

The minimum area of metal used is about 117.78 m².

3 0

2 years ago