Vocabulary
What is an inverse operation?
the opposite operation (ex. addition is the inverse of subtraction)
Netflix charges $9 per month plus a one-time $18 activation fee. The total cost is $81. Write an equation to represent this scenario.
9x + 18 = 81
2x + 1 = 11
x = 5
-2(3x + 4) - 2x = 16
x = -3
A tutoring center charges a $15 registration fee plus $25 per session. The total cost was $140.
How many tutoring sessions were attended?
5 sessions
What is a coefficient?
The number in front of a variable (example: 4x)
Write an equation:
the sum of a number and -9 is 14
x + -9 = 14
-4x - 2 = -18
x = 4
6 - (3x + 9) + 3 = 60
x = -20
A bike rental shop charges a flat fee of $10 plus $6 per hour. If the total cost was $46, how many hours was the bike rented?
6 hours
What is a constant?
A constant is a number by itself, the value doesn't change (example: 9)
Ms. Tew gives you 20 pieces of candy and you eat 2 pieces per day. After a certain number of days, there are 6 pieces left. Using d to represent days, write an equation based on this situation.
20 - 2x = 6
2/3y - 4 = 2
y = 9
58 = 6(-2x+4) - 26
x = -5
Ms. Bowen has 80 pencils which is 6 more than twice the amount of pencils Mrs. Hollifield has. How many pencils does Mrs. Hollifield have?
37
When you see the word "than" when writing an equation, what must you do?
Flip the numbers around!
Write an equation for the words below:
8 less than twice a number is 18
2x - 8 = 18
1/2y + 2 = 15
y = 26
-10.3x - 15 - 11.7x = -37
x = 1
Amy bought b books for $7.50 each and paid $15 for shipping. Her total cost was $75.00. How many books did she buy?
8
What is a reciprocal?
the "flipped" version of a fraction, the numerator and denominator is switched (example: the reciprocal of 3/4 is 4/3)
Jeremy buys 3 identical t-shirts and a hat for $21. He spent $60 total. Write an equation to represent this scenario.
3x + 21 = 60
x/2 - 1.5 = 4
x = 11
2/3( -3x+6) = -28
x = 16
A family starts a road trip with 10 gallons of gas in the tank. They use 2 gallons per hour.
How many hours can they drive before the tank is empty?
5 hours