Answer:
7
Step-by-step explanation:
"a certain whole number" is a number that we don't know, so pick a variable, let's use n
"Twice" means two times, so we'll use 2n for this.
"subtracted from" means the 2n will be AFTER the minus sign.
____ - 2n
What goes in front? "3 times the square of the number" 3n^2
Now we have 3n^2 - 2n
Lastly, we see the result is 133. So this gives us:
3n^2 - 2n = 133 To solve, subtract 133 from both sides of the equation.
3n^2 -2n - 133 = 0 Next FACTOR.
(3n + 19)(n - 7) = 0
3n+19=0 and n-7=0
n=-19/3 and n=7
Since we are looking for a whole number choose n=7
