Let's represent the unknown number with the variable "x".
The statement "Twenty decreased by thrice a number is eight" can be written as an equation:
20 - 3x = 8
To solve for x, first, isolate the term with x by performing operations to move terms around:
20 - 3x = 8
Subtract 20 from both sides:
20 - 20 - 3x = 8 - 20
-3x = -12
Now, solve for x by dividing both sides by -3:
(-3x) / (-3) = (-12) / (-3)
x = 4
So, the number is \(x = 4\).
