Vocabulary
What is the "x" called in the equation 4 + x = 17.
It's the unknown value
Variable
The sum of a number (d) and 20 is 35.
d+20=35
d=15
What is the "+" called in the equation 4 + x = 17
The difference between a number (c) and 26 is 2.
c-26=2
c=28
What is the "4" called in the equation 4 + x = 17?
It's what is being added to or subtracted from the variable.
Constant
6 times a number m is 45
5 friends share the cost (c) of dinner equally. Each person pays $12.
c/5=12
A number (x) divided by 2 is 14.
x/2=14
x=28
To solve the equation 3x = 21 you would need to use the inverse operation to undo what is happening to the variable. What is the inverse operation for this equation?
Division
y fewer than 100 is 15.
You have 3/4 the amount of money (m) that your friend has. You have $20.
3/4m=20 or .75m=20
7 times a number (y) is 14.7
7y=14.7
y=2.1
You are given the equation 3x=21. After you divide both sides by 3 you are left with x=7.
What is the name for x=7? It makes the equation true.
Solution
A number, f, divided in half is 25
f/2=25
Abby spent $27.61 on her last shopping trip. $12.85 was spent on clothes while the rest (f) was spent on food. How much money was spent on food?
12.85+f=27.61 or 27.61-f=12.85
On a triangle all sides have the same length of e. If the perimeter of a triangle is 15in, write and solve an equation to figure out the length of each side.
3e=15in
e=5in