X Marks the Spot
Identify the variable, coefficient, and constant in:
7x + 4
Variable - x
Coefficient - 7
Constant - 4
Is this an equation? Why or why not?
5x + 3
No. It does not have an equal sign so it is a mathematical expression
Solve:
6x = 42
x = 7
A student has some money. She spends $12 and has $35 left.
Let x represent the amount of money she had at first.
Write an equation and solve for x.
x-12 = 35
x = $47
Write an algebraic expression for: 8 less than twice n
2n-8
Find the solution:
x + 17 = -20
-37
Solve:
x ÷ 8 = 7
x = 56
Multiplication undoes division because it is the: ____ Operation
Inverse
Evaluate 4x + 7 when x = -6
-17
Find the solution:
20 - y = -10
30
Solve:
x ÷ 6 = −12
x = -72
A school buys 4 identical boxes of pencils. Each box contains the same number of pencils. The school gives 12 pencils to a teacher and has 100 pencils left.
Let x represent the number of pencils in each box.
Write an equation and solve for x.
4x - 12 = 100
4x = 112
x = 28
Write an expression for:
Half a number n increased by 5
0.5n + 5
Find the solution:
x - (-25) + (-10) = 5
x = -10
A teacher has 169 pencils and divides them equally among x students. Each student receives 13 pencils.
Write an equation and solve for the number of students.
13x = 169
x = 13
A school fundraiser starts with $85. They collect $24 more, then spend $19 on supplies.
Let x represent the amount of money the fundraiser has at the end.
Write an equation and solve for x.
x = 85 + 24 - 19
x = $90
A movie ticket costs $9 per student. A group of students goes to the movies and they buy 2 snacks to share. Each snack costs $4.
Let x represent the number of tickets purchased.
Write an expression for the total cost.
Then find the total cost when x = 5.
9x + 8
(9)(5) + 8 = $53
A school has some students signed up for a field trip.
Then 18 more students sign up, bringing the total to 63 students.
Let x represent the number of students originally signed up.
Write an equation and solve for x.
x + 18 = 63
x = 45
A coach has 72 soccer balls and puts them equally into x bags. After putting 4 soccer balls in each bag, the coach finds 8 soccer balls left over.
4x + 8 = 72
4x = 64
x = 8
A bakery makes 6 identical trays of cookies. Each tray starts with the same number of cookies. The bakery gives away 12 cookies and then divides the remaining 90 cookies equally among 3 delivery boxes.
Let x represent the number of cookies on each tray.
Write an equation and solve for x.
6x - 12 = 90
6x = 102
x = 17 cookies per tray