Addition Principle
5x + 3 = 23
x = 4
x/11 = 0
x = 0
2x = -24
x =-12
What is an expression?
A mathematical combination of numbers, variables, and operations.
x+9 = 15
x = 24
9 was added to each side instead being subtracted
5x - x = 8x +17 - 5x
x = 17
x / -9 = -13
x = 117
-12x = 300
x = -25
What is an equation?
A mathematical sentence stating that two expressions are equal.
3x + 5x = 16 and 8x = 16 are equivalent equations.
No Mistake
11x - x + 33 = 12x + x
x = 11
x/2 + 10 = 4
x = -12
106 = 4x +10
x = 24
What are equivalent equations?
Two equations that have the same solution
-4x = 19 + 13
-4x = 32
x = 8
If you divide each side by -4, your answer will be -8.
51 = 7 - 6x +2x
x = -11
x-8 / 11 = 40
x = 448
2x - 110 = 11x - 146
x = 4
What are terms?
numbers and/or variables separated by addition or subtraction symbols
3x = 7 + 2x
5x = 7
x = 7/5
2(3x - 4) - 9x - 5 = 2x +12
x = -5
2a−5=(2/3)a−3
a = 4
Carlotta spent $35 at the market. This was seven dollars less than three times what she spent at the bookstore; how much did she spend there?
3x − 7 = 35
x=14
What are like terms?
Terms that share the same variable raised to the same power. (if there is no variable it is x0)
5(x-8) - 2x = -4x + 2
5x - 40 - 2x = -4x + 2
7x - 40 = -4x + 2
11x - 40 = 2
11x = 44
x = 4
1. Combining the like terms of 5x and -2x will give you 3x - not 7x.
2. If you add 40 to each side, you will have 42 on the right - not 44.