Let the function P be defined by P(x) = x3 + 7x2 – 26x - 72 where (c + 9) is a factor. To rewrite the function as the product of two factors, long division was used but
an error was made:
22 + 162 +118
2 +973 + 722
+ 7x2 – 262 – 72
-23 +922
1612 - 262
-16x2 + 144x
118x - 72
-118x + 1062
990
How can we tell by looking at the remainder that an error was made somewhere?

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm