Introduction (Kinda)
So you want to write the equation and find the number.
Writing the Equation
Well, the question says "A number s is subtracted from seven. When the result is divided by three, the quotient is two."
If a number s is being subtracted from seven.
7-s
When the result of 7-s is divided by three, the quotient is two. Since your effecting the result of 7-s, you have to put those in parentheses.
(7-s)
Your dividing 7-s by 3.
(7-s) / 3
When you do that, you get 2.
(7-s) / 3 = 2
This is the equation.
Finding the Number
Now you need to solve the equation.
(7-s) / 3 = 2
You need to isolate the s. "Remove" the numbers in opposite PEMDAS order...
Addition and Subtraction
Multiplication and Division
Exponents
Parentheses
7-s is in parentheses.
Divided by 3 is division. So you do that first.
You can multiply by 3 to cancel that out.
(7-s) / 3 × 3 = (7-s)
2 × 3 = 6
7-s = 6
Now that 7-s is on its own side, you can remove the parentheses.
So now to cancel the 7, you subtract 7 from each side (of the equation).
7-s-7 = -s
6-7 = -1
-s = -1
Now to cancel the negative signs, multiply each side by -1.
-s × -1 = s
-1 × -1 = 1
s = 1
Final Answer
The equation is...
(7-s) / 3 = 2
The number is...
1
