Session 4 Math Recording/Lecture-"When a is divided by b..."

[escondido]

This question is taken from the Session 4 recording:
"When a is divided by b, the quotient is c and the remainder is d. Which of the following expressions is equal to d?"

Can someone please explain exactly how the instructor translated the algebra from:
a/b = c, rem = d
to
a = bc + d ?

[tommywallach]

Hey Escondido,

This is actually just an equation that is worth memorizing:

a/b = Quotient + Remainder/b

If you manipulate it by multiplying both sides by b, you get:

a = b * quotient + Remainder

That is actually just a = bc + d, the equation you were asking about.

To prove it, let's look at some random numbers

a = 24, b = 7

24/7 --> quotient = 3, remainder = 3

So, c = 3, d = 3

Now, let's check the equation:

24 = 7 * 3 + 3

Voila! Let me know if this makes sense. Again, the upshot is you just should know this equation, because it comes up now and again on remainder questions.

-t