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3 years ago

X + 4(x + 5) = 40 answer this

Mathematics

1 answer:

Ainat [17]3 years ago

4 0

Distribute
x+4x+20=40
add like terms
5x+20=40
minus 20 both sides
5x=20
divide both sides by 5
x=4

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The sum of the tens digit and the hundreds digit of a number is three times the units digit. 1/5 of the sum of all three digits

Crazy boy [7]

Answer: The numbers are:

965

875

785

695

Step-by-step explanation:

We have a 3 digit number that can be written as:

a*100 + b*10 + c

Where a, b, and c are single-digit numbers.

a is the hundreds

b is the tens

c is the unit.

We know that:

"The sum of the tens digit and the hundreds digit of a number is three times the units digit."

a + b = 3*c

" 1/5 of the sum of all three digits is 1 less than the units digit."

(a + b + c)/5 = c - 1

Then we have the two conditions:

a + b = 3*c

(a + b + c)/5 = c - 1

From the first one, we can write:

(a + b)/3 = c

Replacing that in the other equation we get:

(a + b + a/3 + b/3)/5 = a/3 + b/3 - 1

(4/3)*(a + b)/5 = (a/3 + b/3) - 1

(4/15)*(a + b) = (a + b)/3 - 1

(4/15)*(a + b) - (a + b)/3 = - 1

-(1/15)*(a + b) = -1

a = 15 - b

Then we can give different values for b, and find the values of a and c, where a and c must be positive.

b = 9

a = 15 - 9 = 6

Then:

c = (9 + 6)/3 = 5

(notice that a + b = 15, then c will be always equal to 5, reggardless of the values of b and a).

This number will be:

695.

if b = 8, then:

a = 15 - 8 = 7

and c = 5, same as before.

the number is 785.

If b = 7, then:

a = 15 - 7 = 8

The number is 875

if b = 6, then:

a = 15 - 6 = 9

The number is:

965

4 0

2 years ago

2) 83,97,85,84,96, 80,80,87,91<br> Mean median and mode

marusya05 [52]

$\text {Hi! Let's Solve this Problem!}$

$\text {Before you find the Mean, Medina and Mode you must put the numbers in order.}$

$\text {Before: 83, 97, 85, 84, 96, 80, 80, 87, 91}\\\text {After: 80, 80, 83, 84, 85, 87, 91, 96, 97}$

$\underline {\text {Mean}}$

$\text {To Find the Mean you must Add all the Numbers then Divide.}$

$\text {Add:}$ $\text 80+80+83+84+85+87+91+96+97=\fbox {783}}$

$\text {Divide:}$ $\text {783/9=}$

$\text {The Mean Is:}$

$\fbox {87}$

$\underline {\text Median}}$

$\text {To find the Median you find the number that's in the middle of the set.}$

$\text {Put your Left Pointer Finger on 83. Put your Right Pointer Finger on 91.}$

$\text {Move your Left Finger to the Right. Move your Right Finger to the Left.}$

$\text {Once your Left Finger makes it to 84 and your Right Finger makes it to 87}$ $\text {it shows that 85 is left in the middle.}$

$\text {The Median Is:}$

$\fbox {85}$

$\underline {\text {Mode}}$

$\text {Finding the Mode means finding the number}$ $\text { that shows the most in the number set given.}$

$\text {Since 80 is the number that is showing more than any other number}$ $\text {this tells us that 80 is our Mode.}$

$\text {The Mode Is:}$

$\fbox {80}$

$\text {Best of Luck!}$

4 0

3 years ago

How many atoms are in 882 moles of Li?

kogti [31]

Answer:

One mole of lithium (Li) is equal to 6.022 X 1023 atoms of lithium.

8 0

3 years ago

Read 2 more answers

5. Max and Evie are comparing the number of ride tickets they have for an amusement park. They notice that Evie has 4 less than

Anestetic [448]

Answer:

4n - 4

Step-by-step explanation:

3n-4 = the amount of tickets Evie has

n = the amount of tickets Mark has

3n - 4 + n = 4n - 4

5 0

3 years ago

Plz show work and solve quick please need help!!!!!

Simora [160]

Surface area is just the area of all these 4 triangles plus the rectangle.

First we can find the area of the rectangle.

$\sf A=lw$

Half of the length is 28 cm, so the full length must be 28 * 2 = 56 cm.

$\sf A=(56)(27)$

$\sf A=1512cm^2$

The base for the left and right triangles are 27. The heights would be the net length minus half the length of the rectangle:

$\sf 82.8-28=54.8\? cm$

Calculate the area:

$\sf A=\dfrac{1}{2}bh$

$\sf A=\dfrac{1}{2}(27)(54.8)$

$\sf A=739.8\?cm^2$

We have two of these triangles.

$\sf 739.8\times 2=1479.6\? cm^2$

Now do the other two pair of triangles. The bases for them are 28 + 28 = 56 cm. The heights would be the net width minus the width of the rectangle:

$\sf 81.2-27=54.2\?cm$

Now find the area:

$\sf A=\dfrac{1}{2}bh$

$\sf A=\dfrac{1}{2}(56)(54.2)$

$\sf A=1517.6\? cm^2$

We have two of these triangles.

$\sf 1517.6\times 2=3035.2\?cm^2$

Add all the areas together:

$\sf 1512+1479.6+3035.2=\boxed{\sf 6026.80\? cm^2}$

7 0

3 years ago