Please solve 7d^2-21d?
please show your work
- Anonymous9 years agoFavorite Answer
We have 7d^2 - 21d to solve. Here's the solution:
Given: 7d^2 - 21d
We take out d has the common factor. This gives us:
7d (d - 3) (this is a half equation)
We need to make 7d (d - 3) into a FULL equation. To do this, we'll equate 7d (d-3) to 0. This gives us:
7d (d - 3) = 0
Now we have to ask ourself "what value of d will make the left hand side of the equation equal to 0.
One value is d = 0. If d = 0 then left side will become 0 and we'll have 0 = 0. So thats one answer
another value is d = 3. if d = 3, then the bracket (3-3) will give us 0 and 0 multiplied by anything is 0.
So the answer is : d = 0 and d = 3
For these kind of equations, the idea is to find for which value the equation will balance. (left side = right side).
- 9 years ago
factor it, i.e. take "7d" out of both of them because it is the highest amount that you can divide by in both of them
can you take it from there buddy? solve 7d for zero, and solve d-3 for zero