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3 years ago

The digits of a two-digit number sum to 8. When the digits are reversed the resulting number is 18 less than the onginal

Mathematics

1 answer:

polet [3.4K]3 years ago

7 0

Answer:

Step-by-step explanation:

Given: The sum of two digit number is 8

Reversing the digit will get us number 18 less than the original.

Lets take x as tenth digit of our number and y as unit digit of our number.

As given sum of digit is 8

∴ $x+y= 8$

∴ $y= 8-x$ - equation 1

We also know that reversing the digit will get us number 18 less than the original.

∴ $10y+x = 10x +y-18$

Now, lets put the value of y from equation 1

⇒ $10(8-x) + x = 10x+ (8-x)- 18$

⇒ $80-9x= 9x-10$

⇒ $90= 18x$

∴ $x= 5$

Next, substituting the value of x in equation 1

$y= 8-x$

⇒ $y= 8-5 = 3$

∴ $y= 3$

∴ The original number is 53, sum of the digit is 8 and if we reverse the digit of the number, we get 35, which is 18 less than the original number.

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The number 2400 is first increased by 30%.The value obtained is next decreased by 20%.Find the final number

kvasek [131]

<em>2400 is increased by 30%.</em>

so,

2400 + (30/100 * 2400)

2400 + (30 * 24)

2400 + 720

3120

<em>this number is decreased by 20%.</em>

so,

3120 - (20/100 * 3120)

3120 - (2 * 312)

3120 - 624

2496

therefore, the final number will be 2496.

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3 years ago

4x+6<-6<br> Solve for x put steps

chubhunter [2.5K]

First move the constant to the other side causing it to change sides

4x<-6-6

Then calculate the difference (-6-6)

4x<-12

Now divide both sides by 4

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Then you are left with your answer:

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Hope this helps! :3

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3 years ago

Read 2 more answers

Difference between mafic intermediate and felsic magmas

Inga [223]

Both are indicators of the chemical composition of silicate minerals, magmas and rocks.

Mafic is used for silicate minerals, magmas and rocks that are composed of heavier elements, like magnesium, iron, calcium and sodium. They are dark and have high specific gravities.

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3 years ago

In Lixue’s garden, the green pepper plants grew 5 inches in 34 month. At this rate, how many feet can they grow in one month? (L

beks73 [17]

Answer:

<h2>0.15 inches per month</h2>

Step-by-step explanation:

step one:

This problem is focused on the growth rate of a plant.

given data

the plants grow 5 inches in 34 months

and also that 1 month= 4 weeks

step two:

We can still say that

if 34 months see a growth of 5 inches

then 1 months will be X inches

cross multiply we have

X= 5/32 inches

step three:

converting this number to decimal we have

X= 0.15 inches per month

Therefore the growth rate would be

0.15 inches per month

5 0

2 years ago

A 6m ladder leans against a wall. The bottom of the ladder is 1.3m from the wall at time =0sec and slides away from the wall at

icang [17]

Answer:

- 0.100

Step-by-step explanation:

Length of the ladder, H = 6 m

Distance at the bottom from the wall, B = 1.3 m

Let the distance of top of the ladder from the bottom at the wall is P

Thus,

from Pythagoras theorem,

B² + P² = H² .

B² + P² = 6² ..............(1) [Since length of the ladder remains constant]

at B = 1.3 m

1.3² + P² = 6²

P² = 36 - 1.69

P² = 34.31

P = 5.857

Now,

differentiating (1)

$2B(\frac{dB}{dt})+2P(\frac{dP}{dt})=0$

at t = 2 seconds

change in B = 0.3 × 2= 0.6 ft

Thus,

at 2 seconds

B = 1.3 + 0.6 = 1.9 m

therefore,

1.9² + P² = 6²

P = 5.69 m

on substituting the given values,

2(1.9)(0.3) + 2(5.69) × $(\frac{dP}{dt})$ = 0

1.14 + 11.38 × $(\frac{dP}{dt})$ = 0

11.38 × $(\frac{dP}{dt})$ = - 1.14

$(\frac{dP}{dt})$ = - 0.100

here, negative sign means that the velocity is in downward direction as upward is positive

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3 years ago