Algebra terminology
What is a variable?
An unknown number that is represented by a letter.
x + 3 = 8
5
2x = 18
9
Expand:
3(x + 4)
3x + 12
three more than double a number is nineteen.
2x + 3 = 19
What is the most common letter chosen for algebra?
x
x - 3 = 8
11
3x + 4 = 16
4
Expand:
2(x - 12)
2x - 24
Five less than three times a number is four.
3x - 5 = 4
x + 4 = 2
-2
5x - 3 = -13
-2
-5 (-2 - x)
10 + 5x
Mrs. Stapleton shares twenty-four timbits with her class. If she now doubled what she had left, there'd be ten. How man did she start with?
2(t - 24) = 10
For example double a number is twelve.
The equals sign.
2x = 12
x - 3 = -7
-4
-3x + 2 = -7
Solve:
6(x + 3) = -12
x = -5
A cell phone plan charges a flat rate of $40. Each text message costs $0.10. If your cell phone bill is $58.70, how many texts were sent?
And solve!
0.10t + 40 = 58.70
187 texts
The product can be written as the sum or difference of two products.
The distributive property
-x + 3 = 0
3
-8 = -8 - 3x
0
Solve:
3(2x - 4) = 0
x = 2
Thirteen more than eight times a number is negative forty.
And solve
8x + 13 = -27
x=-5