Let's divide the sentence to translate it to a mathematical language:
"Three times x" means 3x.
"x decreased by 2" means x - 2
"Three times x is equal to x decreased by 2" means 3x = x - 2
Let's solve for x:
3x = x - 2
Subtract x from both sides:
3x - x = x - x - 2
2x = -2
Divide both sides by 2:
2x = -2
(2x)/2 = -2/2
x = -1
Hope this helps! :)