A letter used to represent an unknown number
What is a variable?
You earn $15 per hour at your job, and pay $2.50 both ways for the bus. Write an equation to represent how many hours it will take to make $100 for the day.
what is 15x - 5 = 100
Solve for x:
-9x + 1 = -80
x = 9
Solve for y:
5y - 11 = 49
y = 12
Solve for v:
2(4v+2) = 28
v = 3
The opposite of addition
&
The opposite of multiplication
What is subtraction?
What is division?
For the school dance they had to buy decorations for $50. The DJ charged $30 per hour. Write an equation to represent how many hours you can hire the DJ with $170.
what is 50 + 30x = 170
Solve for m:
-4m + 5 = -15
m = 5
Solve for x:
x/8 + 4 = 13
x = 72
Solve for n:
-5(2n − 10) = -30
n = 8
The "opposite" of a fraction (how you "undo" fractions)
What is the inverse?
You can rent a computer from the store for $2.95 for the first day, it will cost $1.50 for each additional day. Write an equation to represent how many days I kept the computer if I paid $8.95.
what is 1.50x + 2.95 = 8.95
10 - 6v = -104
v = 19
Solve for a:
-8a + 1 = -23
a = 3
Solve for v:
3(v + 9) = 6
v = -7
The number in front of/next to the variable
What is the coefficient?
A family of 7 buys tickets to the circus, they also bought snacks for each person, the snacks were $6. Write an equation to represent how much tickets cost if they spent $147.
what is 7(x+6) = 147
Solve for x:
−9x − 13 = −103
x = 10
Solve for b:
(b/-8) + 10 = 4
b = 48
Solve for x:
2(−6x + 4) = −40
x = 4
What is
1. Remove the constant
2. Remove the coefficient
When going on vacation I took $1,800 with me, if I spend $30 a day, how many days will it take for me to have $600 remaining? Write an equation to represent my vacation spending.
what is 1800 - 30x = 600
An auto rental agency offers a rate of $38.00 per day plus $0.30 per mile. After a one-day rental, the bill was $74. How many miles were driven? Write and solve an equation.
38 + 0.30m = 74
120 miles
The computer club sells 50 more than 3 times the number of pins the chess club sells. The computer club sold a total of 134 pins. How many pins does the chess club sell? Write and solve an equation.
3p + 50 =134
p= 28 pins
A family buys 4 airline tickets online. The family buys travel insurance that costs $19 per ticket. The total cost is $752. Let x represent the price of one ticket. Write and solve an equation.
4(x+19) = 752
x = $169 per ticket