What digits makes 3,71? Divisible by 3 (connections academy unit test)
1 answer:
Since we know that a number is divisible by 3 if the sum of all digits is divisible by 3.
Let us check which digits will make 371? divisible by 3.
11 is not divisible by 3.
Now let us check other digits as well.
12 is divisible by 3.
15 is also divisible by 3.
18 is divisible by 3 as well.
Therefore, 1, 4 and 7 in tenth place will make our number divisible by 3 and our numbers will be 3711, 3714 and 3717.
You might be interested in
Step 1: Factor 
1. <span> Multiply 2 by -2, which is -4.</span>
2. <span>Ask: Which two numbers add up to -3 and multiply to -4?
</span>3. <span>Answer: 1 and -4
</span>4. Rewrite
as the sum of 
and 
Step 2: <span>Factor out common terms in the first two terms, then in the last two terms.
</span>
<span>
Step 3: </span>Factor out the common term
Step 4: Solve for
1. Ask: When will
equal zero?
2. Answer: When
or 
3. <span>Solve each of the 2 equations above:
</span>
<span>
Step 5: </span>From the values of <span>above, we have these 3 intervals to test.
x = < -1/2
-1/2 < x < 2
x > 2
Step 6: P</span><span>ick a test point for each interval
</span>For the interval
Lets pick
Then, 
After simplifying, we get
, Which is false.
Drop this interval.
<span>
For this interval
Lets pick
. Then, 
. After simplifying, we get 
which is true. Keep this <span>interval.
For the interval </span>
Lets pick
Then, 
After simplifying, we get 
, Which is false. Drop this interval.
.Step 7: Therefore,
Done! :)</span>
1. <span> Multiply 2 by -2, which is -4.</span>
2. <span>Ask: Which two numbers add up to -3 and multiply to -4?
</span>3. <span>Answer: 1 and -4
</span>4. Rewrite
Step 2: <span>Factor out common terms in the first two terms, then in the last two terms.
</span>
<span>
Step 3: </span>Factor out the common term
Step 4: Solve for
1. Ask: When will
2. Answer: When
3. <span>Solve each of the 2 equations above:
</span>
<span>
Step 5: </span>From the values of
x = < -1/2
-1/2 < x < 2
x > 2
Step 6: P</span><span>ick a test point for each interval
</span>For the interval
Lets pick
After simplifying, we get
Drop this interval.
<span>
For this interval
Lets pick
For the interval </span>
Lets pick
.Step 7: Therefore,
Done! :)</span>
Answer:
32, 46
Step-by-step explanation:
Remember, a is congruent to b modulo d if d divides a-b.
Now, the problem says that b=4 and d=14.
Let a=32. Observe that a-b=28 and , then 32 is congruent to 4 modulo 14.
Let a=46. Observe that a-b=46-4=42 and , then 46 is congruent to 4 modulo 14.