1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
VMariaS [17]
3 years ago
11

The number 20,2Δ8 is a 5-digit number with the tens digit covered by a triangle. Given that the number is divisible by 7, what i

s its tens digit? I GIVE BRAINLIEST!
Mathematics
2 answers:
Brrunno [24]3 years ago
8 0

I agree with the other person. <u>The answer is 5.</u>

Here's how we can check to see if a number is divisible by 7.

  • Step 1) Remove the units digit to form a truncated (aka shrunken) number.
  • Step 2) Double the digit we removed.
  • Step 3) Subtract that result from the truncated number.

If the result of the third step is a multiple of 7, then so is the original value itself. We can repeat the steps to progressively shrink the values down so we have something more manageable.

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

Let's use those steps to see if 20,258 is a multiple of 7

  • Step 1) Remove the '8' from 20258 to to get 2025
  • Step 2) Double the 8 to get 16
  • Step 3) Subtract 16 from 2025 to get 2025 - 16 = 2009

It's not clear if 2009 is a multiple of 7 or not; however, we can apply the same three steps to shrink the number down. This process can be repeated as many times as you like.

  • Step 1) Remove the 9 from 2009 to get 200
  • Step 2) Double the 9 to get 18
  • Step 3) Subtract to get 200-18 = 182

Like before, the result 182 is fairly big and it's not clear if we have a multiple of 7. Luckily, we only need to do one more round of those steps.

  • Step 1) Remove the 2 from 182 to get 18
  • Step 2) Double that value we removed to get 4
  • Step 3) Subtract to get 18-4 = 14

The result 14 is a multiple of 7, which means that 182 is also multiple of 7. By a domino-like chain reaction, the values 2009 and 20258 are also multiples of 7.

Notes:

  • 182 = 26*7
  • 2009 = 287*7
  • 20258 = 2894*7

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

We've just verified that 20258 is a multiple of 7. Let's go over an example a non-multiple of 7. I'll add 1 to the number 20258 so we are guaranteed that it cannot possibly be a multiple of 7. Doing the round of steps as shown above should get us to some smaller non-multiple of 7.

  • Step 1) Remove the 9 from 20259 to get 2025
  • Step 2) Double the 9 to get 18
  • Step 3) Subtract: 2025 - 18 = 2007

Repeat the steps until we get something more manageable

  • Step 1) Remove the 7 from 2007 to get 200
  • Step 2) Double the removed digit: 7*2 = 14
  • Step 3) Subtract: 200-14 = 186

Let's do one more round

  • Step 1) Remove the 6 from 186 to get 18
  • Step 2) Double the digit removed: 2*6 = 12
  • Step 3) Subtract: 18-12 = 6

The value 6 is not a multiple of 7, and neither are 186 and 2007 and 20259.

If you have your calculator with you, then you should see that dividing any of those values over 7 will not lead to a whole number result.

  • 186/7=26.57
  • 2007/7=286.71
  • 20259/7=2894.14

This is a fairly quick and efficient way to check divisibility by 7 if you are in a hurry.

Sati [7]3 years ago
6 0

Answer:

20258. The missing digit is a 5

Step-by-step explanation:

Ok, let's write the number in a more creative way.  That's 21 000 - 700 = 20 300,  minus something else. That something else has to be a multiple of 7, be less than 100, and has to end with a 2. Now start writing down the multiplication table for 7 and find how many of them ends with 2. 42 comes to mind, and that's the only one. (you can go up to 7x14=98 before having one digit too many).

That brings your number to be written as 21000-700 -42 = 20258.

In theory there was a criteria to see if a number was divisible by 7, but I've never learned it.

You might be interested in
Solve each equation x-6=8
jok3333 [9.3K]
Equation is
x-6=8
x=8+6
x=14
X equal to 14
8 0
3 years ago
Need help on this asap!! Also Thank you in advance!!
sattari [20]

Answer:

31.96 centimeter is the answer

5 0
3 years ago
Read 2 more answers
a truck that can carry no more than 6400 lb is being used to transport refrigerators and upright pianos. Each refrigerator weigh
Tems11 [23]
I'm not going to do the entire question, but I'll do the first part.

For the first part, you have to set up an inequality. Use context clues, such as no more than (the one used in this sentence) to figure out what the symbol should be for the inequality.
In this case, because it is NO MORE THAN 6400, it would be:

6400\leq250r + 475p

where r represents the # refrigerators, and p represents the # pianos


Now that you have the equation, make the graph, then for the 3rd part, plug in 12 and 8 to r and p to see if it keeps the inequality true.

Hope this helps! :)
7 0
3 years ago
Read 2 more answers
Bababoe pls help meeee
mihalych1998 [28]

Answer:

Exact answer is 0.00076232

Step-by-step explanation:

i can give give u a website that does this, if u want

3 0
3 years ago
Kim got her pay raise, and her hourly pay went from $12 to $14. Jane also got a raise, and her hourly pay raise went from $13 to
Contact [7]
Kim because just cause man. 14/12 can be turned into 7/6... boom knowledge??
7 0
3 years ago
Read 2 more answers
Other questions:
  • Find the area of triangle DEF with vertices D(-1,2), E(3,-2) and F(-2,-2).*
    8·1 answer
  • What is 108 minus 36 explain please
    13·1 answer
  • Simplify:<br><br> 2(4p – 3) + (p + 7)<br> A. 5p + 1<br> B. 5p + 4 <br> C. 9p + 1<br> D. 9p + 13
    8·1 answer
  • 8. If BD BC , BD = 5x – 26, BC = 2x + 1, and AC = 43, find AB.
    12·1 answer
  • Find the 61st term of the following arithmetic sentence
    11·2 answers
  • Solve for n. 11(n – 1) + 35 = 3n n = –6 n = –3 n = 3 n = 6
    9·1 answer
  • What 3D figure will create a rectangle if you take a cross-section perpendicular to the base? A. Cylinder B. Rectangular Pyramid
    11·1 answer
  • A number five times is twenty five.
    11·2 answers
  • Can someone please help me
    9·1 answer
  • a monument that is 169.4 ft tall is built on a site that is 67.3 Ft below sea level how many feet above sea level is the top of
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!