Expand \(-(3-c)(c+2(3-c))\).What is the sum of the coefficients of the expanded form?
- (3 - c)(c + 2(3 - c)) = - (3 - c)(c + 6 - 2c)
= - (3c + 18 - 6c - c² - 6c + 2c²)
= - c² + 9c -18
Which coefficients do you mean?
I think it's -1, 9, -18.
Another cool trick you can use to find the sum of coefficients is to just plug in c as 1.
This works because the final answer in expanded form will look like xc^2 + yc + z, and if c = 1, x1^2 + y1 + z = x + y + z, which is the sum of the coefficients. :))