Question

how do you simplify 3j cubed - 51j squared + 210j? I have the answer as j(j(3j-51)
= 210 or is it 3j ((j squared -17j + 70)? thank you for your assistance.

Answer 1

3j^3 - 5ij^2 + 210j
First, we factor out the most obvious factor (which is j, since all terms contain the variable j):
j (3j^2 - 51j + 210)
We can also see here that the terms inside the parenthesis have a common factor of 3, thus,
3j (j^2 - 17j + 70)
To factor the quadratic expression inside the parenthesis, we list all the factors of 70, and from these, we choose the pair that has a sum of -17.
1 x 70 || 2 x 35 || 5 x 14 || 7 x 10
-1 x -70 || -2 x -35 || -5 x -14 || -7 x -10
From these, the pair that has a sum of -17 is -7 and -10. Thus we rewrite the quadratic expression as such:
3j (j - 7) (j - 10)

hope this helps~ `u`

Answer 2

whats 3j cubed