Question

Suppose b is any integer. If b mod 12 = 7, what is 4b mod 12? In other words, if division of b by 12 gives a remainder of 7, what is the remainder when 4b is divided by 12? Fill in the blanks to show that the same answer will be obtained no matter what integer is used for b at the start. Because b mod 12 = 7, there is an integer m such that b = 12m + . Multiply both sides of this equation by 4 and then simplify the right-hand side to find values of q and r such that 4b = 12q + r with 0 ≤ r < 12. The result is q = and r = . Now 0 ≤ r < 12, and q is an integer because ---Select--- . So the uniqueness part of the quotient remainder theorem guarantees that the remainder obtained when 4b is divided by 12 is . Need Help?

Answer 1

Answer:

4b mod 12 = 4

Step-by-step explanation:

Since b mod 12 = 7, it implies that there is an integer, m such that

b = 12m + 7.

We desire to find 4b mod 12

So, multiplying b by 4, we have

4b = 4(12m + 7)

4b = 4 × 12 m + 4 × 7

4b = 4 × 12 m + 28

4b = 4 × 12 m + 24 + 4

4b = 4 × 12 m + 12 × 2 + 4

Factorizing 12 out, we have

4b = 12(4m + 2) + 4

Since m is an integer 4m + 2 is an integer since the operation of adding and multiplication is closed for the set of integers.

comparing 4b = 12q + r with 4b = 12(4m + 2) + 4,

q = 4m + 2 and r = 4

So 4b mod 12 = 4, that is the remainder when 4b is divided by 12 is 4.

Answer 2

In this exercise we have to calculate the value of the unknown, so we have:

the value is 4

we know that the equation will be given as:

$b = 12m + 7$

we need to multiply both sides by 4 to become another known equation, like this:

$4b = 4(12m + 7)\\4b = 4 * 12 m + 4 * 7\\4b = 4 * 12 m + 28\\4b = 4 * 12 m + 24 + 4\\4b = 4 * 12 m + 12 * 2 + 4$

So factoring this equation we will find that:

$4b = 12(4m + 2) + 4$

Thus, when making a comparison between the two equations, we have that:

$4b = 12q + r \\4b = 12(4m + 2) + 4\\q = 4m + 2\\r = 4$

See more about factoring at brainly.com/question/6810544