Definitions
What is the definition of a variable?
An unknown number in an expression or equation.
Solve the following equation:
2x + 7 = 19
x = 2
Solve the following equation:
3x + 3 - 2x = 12
x = 9
Solve the following equation:
3x - 3 = 2x + 2
x = 5
One Solution, No Solutions, or Infinitely Many Solutions
What connects two mathematical expressions to make it an equation?
An equal sign.
Solve the following equation:
.5x - 12 = 8
x = 40
.7x - 3 + .3x - 5 = 0
x = 8
3(x - 6) + 6 = 5x - 6
x = -3
How many solutions does the following equation have:
3(x+2) = 3x - 6
No Solutions
When an equation has different numbers (coefficients) in front of the variable, how many solutions does the equation have (Example: 2x + 3 = 5x +1)?
One Solution
When solving an equation, what kind of operation do we use to eliminate the number or variable from one side - Opposite or the Same?
Opposite
2x + 20 - 10 = 54
x = 22
Lori bought sunglasses and flip-flops at a half-off sale. The flip-flops cost her $24.00. If she spent a total of $21.00 on the two items, what was the original price of the sunglasses?
$18.00
3x + 3 = 7x - 2
One Solution
How many solutions does an equation have if it gives a true statement?
Infinitely Many Solutions
1/3 x - 7 = 2
x = 27
Solve the following equation:
1/3 x + 12 + 2/3 x = 30
x = 18
Solve the following equation:
.25(x+3) =.5(x+2)
x = -1
What value allows you to determine if there is only one solution?
The coefficient or number in front of the variable.
When an equation gives us an untrue statement, how many solutions are there?
No Solutions
What is the term for using the opposite operation?
Inverse Operation
What is something that you need help on to study for the high-grade assignment tomorrow?
Any answer about a topic in the first part of Topic 2.
Solve the following equation:
3(x-5) - 5x = -25 + 6x
(Hint: Check Page 102 of your book)
x = 10/8 or 5/4
How many solutions does the following equation have:
9x + 4.5 - 2x = 2.3 + 7x + 2.2
Infinitely Many Solutions