Video Transcript
William is playing a board
game. From start, he moves 10 spaces
forward. In his next turn, he moves six
spaces back. How many spaces away from start is
he now?
If William begins on start and he
moves 10 spaces forward. On his next turn, he moves six
spaces back. We want to know how many spaces is
he away from start. For this unknown value, we can use
the variable ๐ฅ. What kind of equation can we write
to model the situation? We can write it a few different
ways. First, William went forward 10
spaces. So, we can start with positive
10. And then, he went back six
spaces. We can represent that
mathematically with negative six. If you take positive 10 and
subtract six, youโll get ๐ฅ, the number of spaces away he is from the start. 10 minus six equals four. And that means our ๐ฅ-value is
four.
Currently, the way itโs written: it
says four equals ๐ฅ. But itโs fine to rearrange it in a
more common way: ๐ฅ equals four. 10 minus six equals ๐ฅ is only one
way to model this situation with an equation. We could say that ๐ฅ โ the number
of spaces away from start William is โ plus the six places backwards he walked must
be equal to the 10 total forward spaces. If ๐ฅ plus six equals 10, then we
can solve the problem by subtracting six from both sides of the equation. ๐ฅ plus six minus six equals ๐ฅ
plus zero, which is ๐ฅ, and 10 minus six equals four. Both methods show us that William
is four places away from start.
